If you go the spray & mask, I would also clear coat over the gold. Acrylic & 2-pack base coats arn't very durable on their own, & will wear off eventually
with fuel & polish etc. The old original coach lining was done with enamal which is a poor grade of paint.
You can also get 22ct adhesive, that can be cut into strips but $$$$$. If you haven't got an airbrush etc. the vinyl is an easy way to go, & easy to replace
if need be, but like Trevor mentions, it's not hard to mask up & spray, just make sure there are no kinks in your curves,
CUs