G'day Muskrat,
They used S/rocket springs & collets. The pick at the bottom of the retainers, are the original ones,
I first purchased standard retainers, springs etc. for S/r, but the springs were becoming coil bound
with the high hat retainer set-up, so had replicas made, & all was good. No one could tell me why
the standard set-up was not working!
regards, Cus