When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'm not sure what the seat cushion mod is but anyway the measurements I was going to use are :13" wide x 4"tall with a1 1/2" lip on the top. And it will be 2 1/2" from the bend at the top top the angled cut. I think you will understand if you take a look at the pics again.