Standard 3-pickup configuration I guess where the middle and neck are grounded to the same volume. Must have the bridge and middle in parallel somehow and then.....

Anyone?

EDIT: the volume knobs are wired strangely so that the bridge volume at 5 is actually louder than at 10, and reads around 7.5k. When in the bridge position the neck volume also is activated somehow. Could it be an out of phase mod? Perhaps a question for the wiring gurus in the Tonefreaks section?

If you are up to the task, you might be able to get reasonably close readings (within 1%) from the control cavity if pots are 500k Wulfman, using trial + error method..
It would depend on positions of caps and whether parallel pickup configuration can be decoupled using the pickup selector switch. If you open the control cavity and measure at pickup leads + pot grounds, try all selector switch positions for bridge + middle pickups.
The bridge pickup is probably actually just a little over 8.18k ohms. No idea on the middle pickup, not knowing what is actually in parallel and in series with it, when you measure. It should actually be close to 8k ohms like the other two. So combinations of switch and pot positions might or might not get you close to an 8k ohm reading (try bridge volume at both 0 and 10 since max vol was at 5). If pots are 100k, the error factor might be 7 % or more, and about 2.5 % for 250-300k pots.

I haven't received my new pickups yet, so haven't had a chance to measure circuit loaded pickups vs disconnected pickups yet.

Thanks Udo for the schematic. I'll see what is up later today. The neck position works fine but in the bridge position both volumes/tones are active. The middle position is a nice clear sound as I understand should be the case. Lots of jumper wires between pots so I may just disconnect the middle and see if that makes the neck and bridge positions normal.

I'll add P-90 or mini-Bucker Data below boutique brand pickups on the list, if there are a few entries.

The entire list is the attached text file below
Entries to date are posted here:

Greco EG + EGF series
U-1000
U-2000
U-3000
U-4000
PU-0

PU-2
neck 8.34 k bridge 8.55 k 1980 wulfman
Neck 7.61K bridge 7.36 k JDB
neck 8.24 k bridge 8.48 k 1980 reborn old
Alnico 5 Dry Z
neck 7.27 k bridge 7.72 k James
neck 6.90 k bridge 6.91 k JDB
Alnico 3
Dimarzio

Tokai
Gotoh '57 PAF
neck 7.8 k bridge 7.5 k
Alnico
Dimarzio
neck k bridge 13.68K k (super distortion)
Alnico
Gotoh Mk2 vintage Keiyo Mk2
neck 7.64k bridge 7.84k 2011 reborn old
neck k bridge 8.39k 2010 reborn old
Alnico

Bacchus
BLS-120 8.19 neck 8.17k bridge wulfman
Classic neck 8.5 k bridge k ohms (Bacchus spec)
BLP-59

Burny
VH-1
neck: 7.73 k bridge: 7.75 k
neck 7.43K bridge ???
Alnico VH-2
neck 7.88 k Bridge 7.75 k James T
Alnico VH-3
neck: 8.09 k middle: 7.69 k bridge: 7.71 k Jacco
neck: 8.09 k, bridge: 7.71 k
Neck 8.16 k Bridge 8.13 k wulfman 1987
Neck: 8.08 k Bridge: 8.16k wulfman 1984
Neck-8.39 k Bridge-8.48k JDB
Alnico ceramic
VH-4 dirty lady

L8000

L8001
neck: 7.25,k bridge: 7.38 k
neck: 7.87 k bridge: 7.98 k Jacco
neck 7.85 k brigde 8.06 1981 muccax
Alnico

Ibanez
Super 58
neck 7.5-8.0 k ohms 7.52 k actual
bridge 7.5-8.0 k ohms
Alnico 3 Super 70
neck 7.5-8.0 k ohms 7.92 k actual
bridge 7.5-8.0 k ohms
Alnico 8 Super 80
neck 7.5-8.0 k ohms 8.5 k actual
bridge 7.5-8.0 k ohms
Alnico ceramic V2
15.5k ohms
Alnico 5

Gibson
Original 57 PAF
7.4 k - 7.8 k
7.3 k - 7.6 k 58 Cust LP Forum
Alnico 2, 3, 4 + 5, then shorter 5's T- Bucker
neck 7.34 k ohms
bridge 7.5 k ohms
Alnico 5 Burst Bucker PAF
bridge 7.5 k ohms
Alnico 2 Burst Bucker 1
neck 7.5 k ohms
Alnico 2 Burst Bucker 2
neck 8.3 k ohms
bridge 8.3 k ohms
Alnico 2 Burst Bucker 3
bridge 8.5 k ohms
Alnico 2 Burst Bucker V (Pro) 1
neck 7.85 k ohms
Alnico 5 Burst Bucker V (Pro) 2
bridge 8.4 k ohms
Alnico 5

Boutique and 3rd party Brands:
Seymour Duncan
59
Antiquities
Seth Lover

Dimarzio

Bare knuckles

Lindy Fralin

Sheptones

Tom Holmes

Lollar

------------------------------------------
Alnico magnets weakest to strongest: 3,2,4,5,8 ceramic (6 ?,7 ?)
Asymmetric wound pickups will have lower effective resistance values.

Perhaps I don't understand, but I believe asymmetric coils just have differing numbers of turns on each bobbin, or differing permeability / size of the pole pieces. Since you're measuring the DC resistance of the coils in series, it shouldn't matter.

Here's 4 sets of Dry Z measurements from my own collection, measured on the cable, not direct

1980 EGF1800 1
200102
-neck: 7.51
-bridge: 7.45

1980 EGF1800 2
200804
-neck: 7.67
-bridge: 8.19

1980 EGF1800 3
201121
-neck: 7.53
-bridge: 7.47

1981 EGC1000
210605
-neck: 7.25
-bridge: 7.22

Do have data of 5 more sets but am afraid to corrupt the info if someone with the same set posts (and I don't know where they came from anymore or how they were measured).

I swapped pickups in one of my LP's yesterday. The neck pickup was too hot originally. Measuring pickups both in and out of circuit with 500k pot setups
here is what I got:
Unconnected pickups: #1-7.98k, #2-8.54k, Both in parallel -4.13k (center toggle pos)
In Circuit @ cable end: #1-7.85k, #2-8.43k, Both in parallel -4.07k (center toggle pos)
In Circuit @ pup leads: #1-7.85k, #2-8.43k, Both in parallel -4.07k (center toggle pos)

Center toggle readings are consistent with parallel pickup values using Ohms law -> 2 resistances multiplied then divided by sum of both pup resistances.

Although untested, this correction factor table should give a close approximation of your out of circuit pickup values.

With that pickup toggle selected and volume on 10, you just need to measure resistance of your pickup from the end of an amp cable,
then select your pickup reading and volume pot value in the table below, and multiply the resistance you measured by the correction factor to give you a value fairly close to out of cuircuit pickup readings. The actual value of your pot might differ from it's reported value and there might be meter tolerance error, but resistance of your amp cable and internal guitar wiring add up to about 10-12 ohms.

7.00 k pup w 500 k pots = 1.0140 x ohms value at cable end
7.25 k pup w 500 k pots = 1.0145 x ohms value at cable end
7.50 k pup w 500 k pots = 1.0150 x ohms value at cable end
7.75 k pup w 500 k pots = 1.0155 x ohms value at cable end
8.00 k pup w 500 k pots = 1.0160 x ohms value at cable end
8.25 k pup w 500 k pots = 1.0165 x ohms value at cable end
8.50 k pup w 500 k pots = 1.0170 x ohms value at cable end
8.75 k pup w 500 k pots = 1.0175 x ohms value at cable end
9.00 k pup w 500 k pots = 1.0180 x ohms value at cable end

7.00 k pup w 300 k pots = 1.0233 x ohms value at cable end
7.25 k pup w 300 k pots = 1.0242 x ohms value at cable end
7.50 k pup w 300 k pots = 1.0250 x ohms value at cable end
7.75 k pup w 300 k pots = 1.0259 x ohms value at cable end
8.00 k pup w 300 k pots = 1.0267 x ohms value at cable end
8.25 k pup w 300 k pots = 1.0276 x ohms value at cable end
8.50 k pup w 300 k pots = 1.0284 x ohms value at cable end
8.75 k pup w 300 k pots = 1.0292 x ohms value at cable end
9.00 k pup w 300 k pots = 1.0300 x ohms value at cable end

7.00 k pup w 250 k pots = 1.0280 x ohms value at cable end
7.25 k pup w 250 k pots = 1.0290 x ohms value at cable end
7.50 k pup w 250 k pots = 1.0300 x ohms value at cable end
7.75 k pup w 250 k pots = 1.0310 x ohms value at cable end
8.00 k pup w 250 k pots = 1.0320 x ohms value at cable end
8.25 k pup w 250 k pots = 1.0330 x ohms value at cable end
8.50 k pup w 250 k pots = 1.0340 x ohms value at cable end
8.75 k pup w 250 k pots = 1.0350 x ohms value at cable end
9.00 k pup w 250 k pots = 1.0360 x ohms value at cable end

7.00 k pup w 100 k pots = 1.0700 x ohms value at cable end
7.25 k pup w 100 k pots = 1.0725 x ohms value at cable end
7.50 k pup w 100 k pots = 1.0750 x ohms value at cable end
7.75 k pup w 100 k pots = 1.0775 x ohms value at cable end
8.00 k pup w 100 k pots = 1.0800 x ohms value at cable end
8.25 k pup w 100 k pots = 1.0825 x ohms value at cable end
8.50 k pup w 100 k pots = 1.0850 x ohms value at cable end
8.75 k pup w 100 k pots = 1.0875 x ohms value at cable end
9.00 k pup w 100 k pots = 1.0900 x ohms value at cable end

If your guitar is wired differently your results may vary,
but 1-2% differences are what you should expect for a 500k ohm pot, about a 3% difference for 250-300k pots and a 7-8% difference with a 100k pot.

Unfortunately, I don't have any Les Pauls with 300k or 100k pots, to confirm my findings.
Moving the other volume and both tone pots through their entire range have no effect on readings with modern wiring, as long as this pickup is toggle selected.

A little digression, and not a pickup reading per se, but an mp3 of an early 70's famous Japanese guitarist Naruse playing an early 70's Greco EG-360 through a Fender Blackface and explaining the different tones. Pickups should be something like pre U-1000s I guess.