Ok, first off I feel like I'm missing something so ridiculously simple as to be laughable.
I just got a new (to me) saddle that has a Blevins buckle style that I haven't seen before. The pegs are vertical on the Blevins. One single row of holes on the stirrup leathers and two vertical pegs. I can only get the Blevins slide to lift barely above the bottom peg. Then it locks up and won't slide further. Not enough distance to actually get the stirrup leather off the lower peg. And even if I could get it off that one peg, I still can't even access the top peg to be able to adjust the stirrup leather.
What am I doing wrong? Do I need to force it?