When I had to fix the 797 car, I had simple hubs machined from round solid aluminum stock. They basically look like a top hat, with the 5 studs sticking up through the "brim". Bore out the center, for the spindle, and have them turn each end to use your original bearing races. Heat the aluminum in hot oil, or the oven, and assemble the races/bearings directly onto the spindle to pull the bearings in dead straight (if you pound the races into the bare aluminum, it'll gall and they'll be crooked). I actually start with the races pretty hot, also. I know that sounds goofy, but the steel doesn't grow much and if it's cool the aluminum grabs it pretty quick...learned that trick putting sleeves into motorcycle cylinders.
Mine were done by a custom wheel fabricator (any of the small aftermarket wheel companies can do it, and they already have the jigs set up for 5 on 4 1/2). I think it ran about 150 bucks...they seemed to think it was a pretty easy job, compared to the fancy stuff they are normally doing. I don't have a name anymore...it was just one of those little outfits that come and go as wheel styles change, and a friend made the arrangements while we were scrambling to get the car ready.
One catch...your wheel center hole needs to big enough to keep the aluminum pretty thick.
Hope this is useful for somebody.
Regards, JimL