clk71, No, you don't want to take the bearing stop plate (p. 84) off unless you have removed the whole handle box from the cabinet.
Don't even think about it in your worst nightmare.
Terry, unless you see new soldering on your reel wiper boards, there is little chance they are at fault.
You can make marks on the boards with a sharpie, and for each index position, put a mark and note of the symbol there.
Then you can verify by that that the reel strips and the reel discs are correct or not.
Usually the deepest cuts are the highest pays, however, if you are working on a 5 line criss cross, then all bets are off, and you will find much madness.
You can test the pay circuitry through the reels by putting your VOM or continuity tester onto the 90 wires on the 3rd reel and working your way through to the pay wires leaving the 1st reel going to hopper payboard. Of course the pays must be on correct line.