Help!!! Hairpin slipping.

Hi, I am Tate. Big red headed guy that has been on a couple of rides and plans to do it again. I recently put my RBR hairpin seat on my Moon Eyes with a laid back post. The mount that came with it is absolute crap. I used another from my stock and modded it to fit both rails. That works but I would really like a better setup cause it still moves. Soooo I need to find a clamp for a four rail hairpin that works or, someone who is willing to work with me to weld it on there.