I am traveling this week, so am unable to go out and make a direct check with my 280 SL. First off, you will need to pull off the large air hose to the intake manifold. Just remove the two large clamps, and with some careful prying and such, you can pull off the big corrugated air hose.
After that with the other hoses removed (for idle air) the top of the air cleaner will twist out of the front lug and then lift off.
There is one hose to the water pump that does have a molded set-up, one end is larger than the other. The other hoses by the alternator are standard cut to fit. As I wrote above, I am not at home, so am unable to look up the dimensions (others will be able to chime in on this).
Since you listed a part number are you using the parts book, or do you have access to the on-line, electronic parts catalog (EPC)?