most sewing machine repair places can work on a vintage sewing machine but most of them will not work on the beauty aspect of the machine. just the typical tuneup/repair type work.
i've found its cheaper to have a second machine that you strip for parts then it is to buy parts - most places charge high dollar for vintage prices but you can pick up inexpensive machines on craiglists that aren't pretty and therefore cheap and you just take the parts off it as needed.
i actually picked up 2 machines for free that i use for spare parts.