I have "a '90 radio" I would give ya for a song (after I get my aftermarket working)... why because when you touch the treble knob or the balance/fade knobs is pops static and crackles... once you set it and leave it alone it is fine, but it is obvious that the internals are starting to let go. Why did I put it in quotes, well because the PO before the PO of mine ripped the radio out, cut the harness, and just did a lot of stupid crap - I am quite sure that the dealer in between him and the last PO (also part of my family) just grabbed any Ford radio and stuck it in, it looks identical to the one in my '89 topaz: cassette, am/fm1/fm2 - probably identical to yours, a Ford factory radio from about that era.
I decided to fix all the wiring, replace the missing speakers, etc etc etc and eventually I gave in and bought an aftermarket radio to mount in the hole - dash panel is out to do wiring and all the rest of the what not, so stereo is not fully installed yet.
I wont be sending it with the plastic C clip that straddles the rail though. Shipping might be worse than just going to the junkyard, around here they charge you for nice aftermarkets but just frown and wave you past and go "get outta here kid" for the "junk factory radios".