I can't determine if either Viscera or DIP have a manufacturer's website. (That's the makers of my top two wheel choices.)
I like what you did to get the wheels (you wanted) to fit you vehicle. It shows great initiative. But, seriously, how did someone mount and perfectly remove the material necessary? Can a machine shop with a lathe do that? I'd wonder about inducing run-out.
Wasn't it possible to replace the cap screws with some other fastener? Or modify the heads vs. the wheels?
It looks like you made the first 1/4" of the centerbore 10mm larger. Are those 305's something like 100mm (that was so close it just quite didn't fit?) Can't say I've heard of anyone reporting your particular issue!
Tom4bren: Thank you for your response too. You can't weld plastic caps, but I guess you could glue in the correct chromed piece as you describe.