I've just purchased two open reel machines and they need to be serviced.
You might try the newsgroup rec.antiques.radio+phono .
I'm in the Philadelphia area and can't find any electronic repair shops
that are still in business.
I'd think that in a place the size of Philadelphia, there would still be
at least one or two. Probably nobody advertises "tape" or "stereo"
service anymore, but try a "TV" shop - you might at least get pointed in
the right direction. Some of the electronics chains (Circuit City, etc)
have disservice departments - they won't be able to fix it for you, but
the manager there might know of a local shop that will. You might even
try visiting the two or three Radio Shacks that are closest to you and
asking the oldest person at each one about it. Or, call your favorite
radio station during business hours and ask for the engineering
department - the station will have gone digital long ago but the engineer
may know of a shop that can help you.