I also am looking for a some S Plus parts, first being, ram clear chip and the set chip? just to have even if I don't need to clear it. I may need the jackpot reset key and switch, (the one in it is buggered good) if I don’t have a spare one, I have not looked thru my parts yet, i jumped the switch with a button that works fine for testing and going thru the settings and tests. The SP/SS chips it has in it are SS4712 and SS827, May need MPU board (10Mhz version) if that is what ends up giving the 42 error, have a few more tests and checks to do.
Thanks
Chris