Ok, so here is where I am at - I made my first ever fiberglass seat, which was a great learning experience. I like the shape and am almost finished shaping it, bondo coming soon. I have a delima though, I have noticed some flex where the bumpstop and the seat area attached. I may have made it a little too small of an area on the sides. I think it should be fine, but am looking for some re-assurance from people who know. My other option is to use an old tank I have laying around. So here is my question(s) - will the seat with a little flex in that spot be o.k.? AND what is the differences in seat designs? rounded back, squared back, seat cover with snaps, etc... was there any ryme or reason to them or just personal choice? I will try and post a pic of what I have so far a little later today. Thanks.