Nice find. I looked the pedal up and I'm sorry to say I can't be of much help. That particular pedal was a later version of the original Slingerland black Super Speed pedal. The black version used compression springs, like the Ludwig Speed King, instead of the standard expansion type springs you have on your model. The compression springs were located inside the pedal frame where you removed those top caps. The black pedal had no beater angle adjustment. I had moved on to other pedals after the Super Speed and never got my hands on one of the Yellow Jackets so I really don't know. Good luck with your search. I'll be following along.