When I repainted my GY8 71 GTX, the color was lighter and the metalic was softer than the original paint. I think gold is the toughest to match.

It would be best, if you want a full match, to find someone who has an electronic "color eye".

You may want to find out what brand pain he used. Humidity, temp, etc, all play a huge part on painting....especially metallics like your shooting.