I've an 84 that the stereo works AND the tape deck . I've got one 83 but I can't remember if I checked that one out thoroughly. I somehow don't think the 83 was working if I remember correctly....not entirely sure on that but sure on the 84.
So I CAN help U out on an 84 for sure. $40. plus shipping.
PM me with your zip (& an regular email if U want pics) if interested.