I visited Steve Potts' workshop today to have him check over the frame and fork for alignment and any other concerns prior to beginning the rebuild.
For the frame, Steve uses a series of fixtures on a flat table. The BB shell is clamped down, and then he sequentially checks the seat tube, dropouts and then finally the head tube.
For the fork, he mounts it in his current fork jig to check the straightness of the steerer, crowns and legs. Then he further checks that the two dropouts are properly aligned.
Both the frame and fork turned out to be remarkably straight --- well within the tolerances he looks for in his work of this generation. So, with no structural issues requiring repair or attention, it’s build time now. Stay tuned.
The bike is in mid build-up. A few issues, but most is all good.
I'm still waiting for the right pedals --- one set is in the mail to me and another candidate is still out there on eBay.
The rear derailleur I'd planned to use (a Suntour ARX) didn't quite work well enough with the 32t freewheel -- so it needs to be swapped from a short-cage to a long-cage model.
The brakes also were a bit tricky... with the preferred Mafac "5-Bump" pads needing a little trimming. That was common though even BITD.
Photo credits (last 2) and great thanks for the impeccable wrenching to Mike Varley at http://www.blackmtncycles.com