Firstfives.org

There is a black steel cylinder, part of the mounting bracket, that appears on the exploded view drawing. Must be old, as there are no parts available for the assembly, to read what the cylinder's function was.
Any input appreciated, including perhaps junking the obsolete thing.

I think it was a pressure dampener, BMW seemed to be big into them for a while. I wouldn't worry any if it was missing, they don't seem to have used them for many years now.