The RS 2004 was a great radio made by GRE.. I had several when they were new.. the radio of course is just old, I got lucky about 5 years ago and picked up one in a pawn shop that looked brand new and did work but since it didn't trunktrack and the modifications that can be made to pick up old analog cell phones are no longer valid I did sell it for spare parts as the display and the keyboard were actually in very good shape.
The guy in the pawn shop knew nothing about it but realized it was obsolete and would not pick up much in our area. I turned it around pretty quickly as he sold it to me for practically nothing and it was a good source for spare parts for someone.
Good luck trying to get a new keyboard as that's what you need