I had almost the exact same issue. Definitely score motor 10b. There are only 2 switches on this cam, it is the top switch. The cams on the Bow and Arrow are bakelite so they don't seem to be as smooth as a cam on a Williams. They may be out of round or possibly have imperfections from one side to the other. A little test you can do is to take something like a pop cycle stick (wood) and place just a little pressure on the top of the switch at cam 10 near the rivet. Hit a target or roll over and you should see some scoring variations or maybe the full 500 points each time. The "good" thing is there are only 2 switches on this stack so it is easy to take off and adjust/clean the top switch. You'll need to adjust the bottom half of the switch "up" so that it has good connection with the top half of the switch. It's this switch that holds the 500 point relay so that cam 2 can pulse the points. Are you having the same problems with switches A, B, C, and D?