It looks to have an Australian girth. The front leather straps on an Australian saddle are normally 1.25 inches, and won't fit into the buckles of an English girth. It took me a long time to get used to Australian girths, but now the only thing I dislike about them is that they are hard to find.
There are converters to western cinches. Unhappily, my horses are slender enough that they don't work well for me, because I couldn't then find a cinch small enough.