Hey Steve,
What you're looking for is a repair guy that has some experience with circuits like this. You'd be lucky to find someone that has calibration tapes but really, since this should be nothing but discrete components, most competent techs should be able to get it working.
The big question is how much you're willing to pay to get it working right. You'd probably be better off finding another one that's already working. Most of these units sell for under $100 and that would cover a little over an hour of labor at most shops.
If you have a buddy that's into DIY audio, you might be able to get him/her to take a look.