i have never heard of the 1 1/8". I have a ton of the 1". Are you measuring the inside of the buckle or from edge to edge? the buckles are measured from the inside where the webbing goes. I'm guessing that you need the 1".
You can contact this seller on ebay as he has a ton of the side release plastic buckles.
eBay Store - Country Brook Design: Plastic Hardware: 50-1-1 2 Triglides Webbing Strapping Slides CBD
If you want a 1", i'll send you one.
