In the scene where O'Connell cuts the "scarab" out of the guys arm, our hero pulls out a knife and opens it one handed. The knife he pulls out is a Benchmade Bali-Song. The handle is pretty distinctive. The knife he uses wasn't manufactured until the 1980's. The film is set in the 1920's. Pretty lazy not to provice him with an appropiate knife.
First of all, you are right about Benchmade, the company it self was originally founded in California 1988, but the Balisongs were dated before 1791 beginning with the Pied-Du-Roy which is French, second, there is nothing distinct about the handle at all, it looks like a common butterfly (balisong) knife.