Sorry but that was a mistake. This forum is full of posts from people who tried shotgun cleaning & adjustments, and caused more problems than they were originally trying to solve.
What to do instead: Slowly and carefully diagnose one problem at a time and then fix only that.

His video is at

I'll need to see a high quality scan of the schematic from (for example) Staples ($2) or Kinkos ($6)

Have a look at the Outhole switch

The Ball Index relay should let go when the Outhole relay activates.

Pinball (resized).png

I have no idea what you're asking here.

The Ball Index relay can be energized by the 10, 100, or 1000 Point relay or the Tilt relay. Once energized, a switch on the Outhole relay and a switch on the Motor should release it, unless one (or more) of the 4 switches are keeping it energized. Make sure those 6 switches are working correctly.

For a switch to work 3 things are necessary
1) When open, there should be a small space between the contact points (duh)
2) When closing, the long blade's contact point should push the short blade's contact point enough to move the short blade
3) The contact points should be clean, which they usually will be if #2 is happening

Pinball (resized).png

Here's the score motor. As we can see from the Motor Sequence Chart on the schematic, cam 11 has 6 bumps per 1/2 revolution. Count back from there to cam 6. B probably means it's the 2nd switch from the bottom, but check wire colors to be sure.

Pinball (resized).png

Pinball (resized).png

Then concentrate on the other switches I pointed to above.

If the Ball Index relay is staying energized when it shouldn't, then something is keeping it that way. What's doing that?