Regarding your findings:
I looked up cam numbers and they have been the same since the 420 came out except in the european version where the number currently in use for US models changes. The US numbers are 117 051 08 01 and 09 01; these numbers chnge to 20 01 and 21 01 after engine number 965: 048805.
Do you know if this was the case for the 560? I thought in '89 or so they started using a cam that wasn't so "soft". Perhaps, they did and didn't change the part # (??)