Hi guys,
are there any differences in the bose radio units (cd with tape version) that were installed in 1990 ZR-1s and standard 1990 C4s?

I guess not because on pictures the systems look equal, but Im not sure.
Reason why Im asking:
In my 90 ZR-1 I`ve got an aftermarket radio installed (it came already with this aftermarket radio) but I want to go back to an original bose radio unit which I had to buy second hand.
So I wonder if I have to pay attention to any restrictions regarding the C4 model.
One more question: does somebody know the part number of the bose radio unit that would fit into a 90 ZR-1?
Thanks in advance!
TNR