[DanEC]

I have the standard brakes and Jag rear suspension on mine so maybe the additional machining has something to do with upgraded brakes. I can't think of anything on my car that looks like it might need, or received, special machining for the adaptors.

Bob, at Vintage Wheels is pretty tecnically savy and provides wheels for lots of ERA cars. Maybe he takes care of it from his end.

Kevin - if you're using FIA wheels are you getting them from Trigo? Maybe it's something specific to them??