Hello,
Yes the second to last set of digits on the part number should be the ID number stamped into the back of the camshaft. So the first camshaft 180 051 0935 should have a "09" ID number stamped into the back end. The second camshaft #114 051 08 35 should be identified with a "08" number stamped into the back end. In addition the whole part numbers are usually cast into the camshaft itself.
The "09" is an original SL camshaft and was replaced in later years with an "02" camshaft. These two camshafts have the same profiles (lift and duration). They both have the same valve opening duration of 142 degrees total of valve opening.
On the other hand the second cam you have "08" will fit and work in the SL if the correct cam holders are used, as naj mentions, however it was originally designed for a later W114 chasis sedan and is a lot tamer. It has only 122 degrees of total valve open duration.
Joe Alexander
Blacklick, Ohio