I will be the first to admit I am certainly no expert in SG's past 68, my knowledge is all centered around the 1960 -65 versions and to a lesser extent up to 68, but that does look to me to be a 1970.
The heel, the cutaway bevels the serial number, the pots (according to your post) and even the case all say 1970. What I find strange is there is no "Made in USA" stamp on the back of the headstock. I would fully have expected to see that on this guitar.
But, everything else says 1970 including the serial number and pots and the solder joints look to me to be original so it is pretty unlikely that the pots were from a different guitar, they look factory original to me.
Just realized there is no volute either. Strange. All 1970 features and dates yet two key things you would expect to see in a 70 are not there, the volute and the "Made in USA".
I'd like to see Solodallas chime in on this one.