Refrigeration Help

Does anyone know of any company or individual that works on and repairs vintage refrigerators? My 1948 GE Frigidaire runs great in the winter but now that the hot weather has come around, the compressor runs and runs. And it is hard pressed to keep cold. I know of one place that rebuilds vintage fridges and turns them into works of art, but i don't want to spent the money that they wanted for the refrigeration rebuild.
So with that being said, looking for someone in the North end. North of Seattle would be great, but if reasonable, Puget Sound region will work.

Thanks, Chris

Have you done the obvious and cleaned the condenser coils on the back?

Take a look, there may be servicing ports on the coolant lines already. If that is the case adding more refrigerant (likely R-12) is possible if you can obtain it. I've worked on the unit on my boat, it isn't rocket science. If you are close to Shoreline I'd come take a look.

The condensers are on the bottom and yes I did clean them. As far as service ports, no, there are none. I started reading about converting to something other than R12, but not sure if that is something the normal person can do or not. Or if I just refill the R12 if that would work.
I want to restore it with new paint and new insulation and i feel that part I can do myself. But not sure about the refrigeration part.
I live North of you in Everett, and if you have any expertise in this, that would be great.