The equipment need to apply the gold tone to most modern watches is extremely expensive. The only way to apply a gold tone finish that is durable is by using a process called “physical vapor deposition" This process actually blasts the base material with the gold tone substance embedding it into the base metal. What this basically means that no hobbyist will ever be able to afford to do this in the garage. Plating with real silver or real gold is a much simpler process believe it or not. I have often wondered what the cost would be if I collected all of my spare gold tone cases that have worn though and sent them all in at once what it would cost. I have actually done an experiment on a $20 eBay pick up of a Seiko with a badly worn gold tone. I took it apart and went at it with the buffing wheel and the black rouge. I was able to burn off all of what was left of the gold and then I finished of the case with a brushed aluminum top and I polished the sides and back to a high gloss. It came out great. Of course this only works on watches that the base metal is aluminum and not one that the base metal is brass!
Michael
Michael