Getting ready to clean up and detail the horn button. Seems to have been originally done as a hot foil applique then painted inside. My foil is flaking and cracked and paint was also flaking off too. Inside also has had a fine dirt staining the plastic for many years. My plan of attack will be to sand with a 2000 grit paper trying to stay off the silver head then polish and then I’m not sure what to do with the foil. If I have to I might be able to leave as is and paint. What paint will not attack the plastic? From the photo Some of the paint is still stuck quite well. Should it all be removed or will a black gloss match well enough. Do not want to scratch plastic getting it off. For those who have already tackled this task your guidance will be appreciated.
I’ve not had to restore mine so what follows is based on general painting experience. It appears the silvering is in good condition, a big plus. I wouldn’t be worried too much about paint attacking the resin but you will want the paint to adhere well. Carefully steering clear of the silvering, I would remove the residual black paint and prep the surface with 1500 grit wet to give the surface a uniformly fine tooth. This will avoid a shade mismatch and visible transition between old and new paint. Shooting with a gloss black enamel should yield a good result. There are paints formulated specifically for plastic but these may contain a solvent that might yield a cloudy result in a reverse reveal application like this one. The fine tooth should be sufficient for a standard enamel. Take your time, and again avoid doing anything to the silvering - there’s no way I know of to replicate it DIY.