Quoted from BlackCatBone:
What do the numbers (50, 1, 5, 32, 6, 12, 31) inside the spotting disc rectangle represent? They aren't the spotting disc lugs, as far as I can tell.
unfortunately, the numbers don't necessarily mean anything useful with the information we have. They are actually the number bally assigned to the wire lug on the engineering blueprint of the contact plate. That number was also used on the rivets that were connected to the lug as a label ... dunno why on some drawings in the manuals (not yours...you don't have a spotting disc diagram - lucky you) they decided to cram the wire id directly on the rivets - up to 5 characters needed instead of typically 2.
problem is, the numbering isn't necessarily sequential around the contact plate. Some games the numbering bounced around, there were gaps, letters were used, etc.
so while the schematic is right in that lug 50 had wire 23-6 on it, that may not tell you which lug on the plate is 50. It definitely won't tell you which/how many rivets are connected lug 50.
so just ignore the numbers in those boxes.
later games had the spotting disc diagram in the manual, and the guy who provided the mixer blueprints for Miami beach is taking a look at making the diagram for the spotting disc ... that means figuring out a few hundred rivets, so it may not be feasible.
on a tangent (because I can't stop myself), you may be amused to look at the single-step circuit for the extra balls...if you have the diagram in the manual. On most games, you cannot single-step to get the ball, you can only single-step to light the first two panels for each ball. That's how bally controlled the odds - you must get the ball via the run-to circuit. Having "extra" lit just made you think you were "closer".