I have the Jane kits model for nickel and zinc plating and whilst I have used it a few times to experiment with quality, in future would only use it (or any home based plating kit) for underside playfield componentry.
There is just too much labour involved for prep work, the plating process and most importantly polishing to get the topside or other visible pieces to showroom condition, so I would be taking them as a bulk lot to the nearest sensibly priced commercial plater to be high polish plated instead.
