hifi engine

Refurbishing a Fisher 500-B in AZ?

I was given a Fisher 500-B a few years back. It still works but I know it could sound better. Does anyone have a recommendation for someone around Mesa, AZ. that does this kind of thing? I know there are places it can be shipped to for this but, well, you all know how heavy these things are. Except for the tubes (quite a variety of brands), this unit has not been messed with and I only have enough experience doing basic repairs. Any information would be appreciated. Thanks, GT