Here is one. How about a little cheater harness, that goes between the board and the existing wiring harness in areas that are notorious for needing re-pinning. These are common on old Bally and Stern games, as well as other areas.
The thing is, the cheater would have special terminals that really bite. If you could eliminate the need for all that re-pinning, that would be quite a time saver and it would seem to be quite marketable for that reason. I should add that this would be useless for cold or cracked solder on board pins, but if the problem was loosely gripping plugs, this would work well in that case.