Hi David C., I've seen rebuild kits
POL has this
https://www.performanceonline.com/1960-62-Chevy-GMC-C20-Truck-Front-Suspension-Rebuild-Kit/ - $833.06
CPP has PN 6062SFK-PT for a much more reasonable $319 but doesn't offer a description, I've emailed them for a parts list.
Did you get one of those?
CPP and POL have kits for 73-87 for $309 and $217, which are both more afforable.
At the time of the OP I'm not sure one was available or maybe I hadn't looked hard enough. In any case I'm pretty much set and ready to go for work on the '87. Its half pulled apart in my driveway, I'm just waiting to get some warmer weather to pull it off an get to cleaning it up and rebuilding it. If it's not good enough to rebuild I guess I'll re think keeping the stock crossmember and rebuilding it. Also I don't see replacement torsion bars anywhere... anyone have any idea where those can be found, or is that what you mean by control arm shafts?