Got another piece finished for the Ben-meya rear derailleur. Had to go back and respray the front plate, paint wasn't sticking. This time I used an acid etch primer and it worked great. Pieces still need a final polish to remove the small scratches on the mirror and to blend the paint lines a little better but I'll wait a couple days for the pieces to fully cure before I do that.
Stuck a screw in there to test the fit, screws I have on order are alloy and gold in colour :-)
So far so good.