Decided to bite the bullet. Sent the crank to Roger at R&D to have it rebuilt with the NOS 22 mm small end rods. I figured since I was already this deep into the engine, it's a good upgrade.
One thing I had a lot of difficulty fitting was the seat, which is a nice looking reproduction seat. When I first installed it, it was totally skewed and the latch didn't line up well. I switched out the hinges for an OEM set that I had and that solved most of the issue, but still took a bit of tweaking those hinges to get it looking acceptable. There's also a slight interference between the rear frame hoop and the grab bar mounting points on the underside rear of the seat pan. Careful measurement and comparing it to an original seat pan indicates that the repro is about 3/8 inch shorter, likely causing the interference. The original pan I have is rusted beyond saving. Anyone have a solid original seat pan they don't need?