I purchase a hard dense
rubber block off eBay (it’s normally used by jewelers). It’s extremely dense, but easy to work with using your normal array of garage tools – drill, saw, sander. It’s also easily formed using sandpaper. I cut it, drilled 2 holes in, and then rounded the ends to follow the lines of the underside of the CF seat. This is what I mounted the front of the seat to. I cut it think enough so that the seat once mounted and bolted, the ribs will clear the “seat mount wings” by about an 1/8″-1/4″