Possible 1917 Officer's Saddle in Unused Condition

I purchased this beautiful saddle at an estate sale, so I don't know it's history. It resembles a 1917 Officer's Field Saddle, from what I have found on the internet. It is made of all leather. The underside appears to be glove leather-it's very soft and smooth, and appears to have hand-stitched quilting. The tree is very unusual, having two padded extensions behind the seat. It has several silver-finish rings, such as to attach accessories, and a crupper bar. It has a 16" padded, smooth leather seat. There are no signs of use on the saddle at all. It appears to be of very high quality. The only makers mark I can find is a circular stamp under the left flap, very high up. Only part of this stamp is visible, and I'm unable to read what it says. I'm including several photos, including one of this stamp. Any help on determining its value will be greatly appreciated.