Herer are my 2 bits worth as an absolute beginner:
1. If the top edge was straight, it may be a pedang or piso pedang from Lombok as discussed by BluErf in an earlier thread. I don't see a ganja so it can't be a keris.
2. The sheath looks like a sandang walikat, but the shape is rather odd. Was it original to the blade or comissioned in the USA?
3. The hilt and selut/mendak looks Balinese/Lombok
Of course, I'll be happy to be proven wrong
That's how we learn