Before transferring the wiring, lights, switches, etc. to a new playfield,
label every component. You can buy plastic wire ties that have writable
labels built in on the ends. Use these to mark every component with a
number. Then, using one of those old sticky tape labelers, put
corresponding numbers beside each component on the old playfield. When you
transfer everything over, the sticky labels left on the old playfield are a
handy reference guide. No more mix ups!