Great score, well worth the elbow grease to get it up and running. I have a RB620 from the same era and it's a fantastic bass.
You could just bend the jack back so it makes sufficient contact for testing purposes. Then connect the pickups, one at a time, directly to the jack to determine if they are working correctly. If so, then get pots and a new jack. If not, then you can get whatever system you desire.
You could just bend the jack back so it makes sufficient contact for testing purposes. Then connect the pickups, one at a time, directly to the jack to determine if they are working correctly. If so, then get pots and a new jack. If not, then you can get whatever system you desire.