FWIW to the OP, I originally built a feng3 JDM (**broken link removed**) and successfully programmed a '2550 with <I think> WINPIC800, IIRC, before discovering I didn't have any suitable substitute transistors/inductor to build a PK2 clone board.
I ordered a genuine PK2 and binned the idea...
I ordered a genuine PK2 and binned the idea...