Thanks 300dOwnder for bringing this helpful page up, and the additional info. I saved a copy for the future.

I removed the lift pump on one of my W123's since that seemed the simplest way to remove the old white hand primer. I recall having to work slowly w/ a 10 mm box wrench to get some of the 3 mounting bolts off. I may not have had my 10 mm ratcheting wrench then, or might not have fit. I took the outlet fittings off to inspect and don't recall any difficulties like mentioned here (minimal rust in CA). Since then, I read the best way to remove the white primer is to just bash off the plastic to get at the bottom nut, assuming you aren't trying to save it.