I have repaired some radios for our members here. I don't ask for a fee but rather I suggest a donation to this site. However I am a long way away in Canada and also I don't work on transistor radios. If you pick up a copy of Hemmings Motor News, you will find people in there that do repairs. Unfortunately I can't speak for them. Another option is to buy a new one specially made to fit your truck. I have one from , I think it is called USA Custom Auto sound or something like that. For me it has been a good product. I used to have one of my original style radios in my truck but the AM band where I live is very poor. I also wanted access to FM and also the ability to play my MP3 player music, so the radio gives me both.
Fred