Try this, go to one of those electronics hobby geek stores and look to see if some kind of machine has parts that will work. I've picked up some good repair parts at these stores. You never know from week to week what some of these stores have. They buy stuff from close outs. One time I saw a stack of old HP plotters for a few bucks each. All sorts of gears in some of them. Another thought, some wiper motor assemblies have simular gears. Most of them are brass.
In Houston there is EPO for Electronic Parts Outlet on the SW side and ACE on the near NW.