I think that you will find that it is a Buick radio. I have the data sheets on the model 981550, a Sonomatic. In general these radios make good donors when converting the truck radio to 12 volts. They have a push pull output stage which gives them almost twice the output power of a single stage output radio like the AD radio. This comes in handy when you want to crank up the base without getting distortion.
If you would like, I can Email you the scanned data sheets. If you need assistance to get it going , we could do that in the forum here. In general, there are ways of relocating the controls to match the dash, if the center dial portion will fit the opening.
