Some of the Gibson 345 have stereo Varitone, the Big D Varitone is mono but it sounds great. Evene more importantly wold be to use some of the best 10% CTS500K pots. They will add clarity and have a smooth custom taper. I also build my 335/345 rigs with 50's wiring, not the stock muddy modern wiring. Here is a pic of a "Lucile" rig I built a month or so back and shipped it to the EU.