I am in the process of rebuilding the ST-300 from my 67 Skylark. When compressing the reverse clutch piston return seat (spring retainer) in order to remove the cylinder from the transmission case, I managed to destroy it. Does anybody have one lying around in their parts bins? Also, managed to lose one of the reverse clutch springs as well! I'll gladly pay for both. To be clear, it's the little cup which retains the springs within the clutch piston.