I have what I believe is a tt350 seat, which has the same sharp upturn as the xt350 seat, but the rear attachment points are distinct from the tw200 seat. the cover is nasty but the pan is usable. It might be useful if you wanted to do a hybrid seats as done by eldavo or ??. Personally I'd consider doing a bit of tweaking to your stock seat pan and then revising the foam to meet your needs. Its actually pretty easy to make the front of the tw200 seat accomodate the steeper slope of an xt350 oem tank and probably equally for the Clarke if thats what you are using. Tom