And another great score, you've been busy. Nice lamination on this one. I don't know about the horn collar being a feature seen only on Borneo barongs, but the experts I'm sure will answer that question for you. I once had a barong that had a collar like this, but was made of bone instead. On the hilt, is that an old repair where the section of wood is missing? It looks to have been intentionally carved out and looks to have the remains of an adhesive still present.
Congratulations to you again on this most interesting piece.
Best,
Robert