Powdercoat Over Chrome ?

Yes it works.  I've had it done many times with excellent results.  The parts are sand blasted.  If the chrome is weak, it usually blasts right off at 200psi air pressure.  You may want to screw thin metal covers to plywood when blasting to keep them from warping.  My blaster guy is really good not to warp stuff.  If the chrome is sturdy, the blasting will rough it up enough for the powdercoat to stick.  I use that special high-heat powdercoat tape (it's white, and kinda cloth-like tape) for large threaded areas, and areas where engine mounts go, etc . . . I plug all small threaded holes with bolts.  Steel or aluminum rims, metal engine covers, hubs, headlight buckets and oil tanks are all good parts for powdercoat.  I still like a painted frame, since powder can look too thick and smooth.  It's great to have local company in the business !