Hey there ~ I recently picked up a 1998 Swr Workingman's 10 for $33.00 At Goodwill. Only thing wrong was a wobbly input jack. Got it home and tried to tighten the hex that secures the jack but it just turns and doesn't tighten. The jack shaft seems to be plastic with threads near the bottom , so probably stripped , but having seen pics of similar amps , the nut doesn't look original so I'm wondering how to secure the jack in place. Thanks for any help.