Have you looked up under the seat jockey (under your leg). Sometimes more identification is high up on the skirt or the underside of the jockey. The strap keeper doesn't appear to be original to the saddle. Quite often saddles weren't identified because of minor flaws that didn't affect the use of the saddle. The manufacturers didn't want to be identified with the saddle and often gave the retailer a deal. The style makes me think of Colorado Saddlery. How's the fleece?
I have looked under the skirt and jockey, but maybe not high enough up. I will look again. I was also thinking that the whole in the attached pic 1 is for some type of tag/marker that was taken off or came off. The fleece appears to be in pretty good shape. In attached pic 2 you can tell the leather ties were lapped over each other. Ii'll do some checking around with regards to Colorado saddlery.
The hole appears to be three holes made with a leather punch. If it were original to the saddle, a slot punch would have been used and it would have straight clean edges. A tag would be on the near side, if the metal plate type and usually under the seat jockey. You have a good quality saddle, likely a roper with a rawhide wrapped tree. I find these saddles very comfortable. The fit is superior to a padded seat. In fact I just bo't a hard seat saddle that was made before 1972 that's like new. I have located numbers up close to the tree but several inches away so that can be read.