Does anyone know or remember how they used to balance OLD VW beetle tires - the 4 lug/stud type without a center hole in the rim? I have an old car trailer from the 70's with rims just like that. The brake drums on the trailer are threaded for the wheel studs, and have centering flanges on them Nowadays, if there was an adapter for a rim like that, it's probably long gone to the scrapyard.