Ome in Boulder Colorado. They are above averge in price, but are wonderful instrucments. I have 2, both open back, but they make bluegrass models (resonators) too. I've never read anything negative on the Hangout about them.
Jimmie Cox used to make all his own parts, not sure if he's still building. Ronnie Bales makes most of his own banjo parts, uses a Blaylock ring. He may be using some Prucha hardware but I'm not sure about that.
Only two I know of who build Gibson type bluegrass hardware & instruments in the USA are Jim Cox & Kel Kroydon. Help me out if I'm wrong here. A lot of builders use Prucha or RK hardware then call the banjo Made in USA. It would be good to define the real builders and assemblers from each other for the HO members. I'd like to know who they are.
Except for the origin of the wood involved, in a Gibson type Bluegrass banjo, a Kel Kroydon with a set of Keith tuners is one of the closest you'll find to be American made, including the OPF and all the other hardware.