It could be done that way. I did it this way for two reasons:
1. Being brass the masters are now good for essentially forever for making new molds as the existing ones wear out without any loss of detail as long as reasonable care is taken
2. Being brass I can use them as masters for vulcanized rubber molds in case I want to do white metal or brass wheels as well. We are working on a Frontenac Model T OHV engine next using the same process and looking at a photo etch frame and suspension (leaf springs) possibly with brass axles, etc.
Part of my idea is everything I have done in resin I can also do in metal and eventually when the engine and frame/suspension are done I can work up the remaining suspension parts and do a complete Model T chassis kit in metal. The only non metal parts would be the tires, hoses, wires, etc.