Wilderness Systems Tarpon Phase 3 AirPro Seat Back Strap

I purchased all the seat straps for my Tarpon 105 to replace the original ones that had disintegrated. The product is correct, and very nice, looks like the original ones. My only issue is with the seat back on the boat, and the place the strap is supposed to thread through on the back of the seat. The gap is too small to thread the buckle through it, and the buckle is sewn on, so can't be removed. And I could not figure out a way to break down the seat back to make it fit through. I was able to alternatively place the strap, where it should work ok.