Misplaced Radio Code

[Wastenott@aol.com]

I am on vacation and blew a fuse last night for the radio circuit.  Radio is
in safe mode. The car is '91 200 wagon.  I replaced the radio earlier this
year with a refurbished one I bought from a company in the mid-west if my
memory serves me with a long German name.  I don't have their number with me
either.  I did write down that is was a BNO radio, the serial number, and a
four digit number that is not the code.   Any suggestions?  
Bob Watts