Originally Posted by
cycle_maven
If it a 26 TPI bottom bracket shell, then I'd punt. Trade it for a square-taper crank, find a new axle and use the original cups.
I like that idea. Years ago (many years ago) I put a Stronglight 93 on my '70 Super Course. The standard threads on the cups that came with the crank were wrong, so I used the originals. They worked fine.
Finding a square taper spindle for the crank you end up with could be difficult. If eBay and your local shop can't help, give these guys a try--
http://www.renehersebicycles.com/. Finding old NOS is their specialty.