Several places to post your questions:
The reference to "GE Stereo Multiplex" probably dates it from the early 1960's (the GE/Zenith method of fm stereo broadcasting was chosen by the FCC from among several competitive formats in 1961).
Here is one source for repair of older turntables:
You may find other links of interest here:
Radio/phonograph consoles of that period are in nearly all cases not of significant interest or value to collectors, and that would include all GE models. The electronics contained in a few other console makes, such as certain Pilot models, may be of limited interest to some.
I would not conclude from the information in your post that the radio/phono is necessarily a GE; it is possible that the turntable may be made by GE, and the FM receiver may utilize GE technology under license, but be made by someone else. I suspect that "RC7130A" is the model number of just the turntable. I'd suggest looking at the rear of the radio chassis, the cabinet, and the speaker, and seeing if there are any additional make or model numbers indicated anywhere.
If you want to sell it (and I suspect it would not bring more than perhaps $25 or $50, if it is in fact a GE, and assuming that you can find a buyer at all), I'd suggest looking at the list of antique radio clubs in the second link I provided above, and if there is one that is local to you, contacting them and seeing if it can be offered to their membership via their website or a bulletin or periodical they may publish for their members. Or else place a local classified ad in a newspaper or buy/sell publication.