I think it was EZRIDER280 (?) that replaced his with all manual. Beautiful car also. It can be done.
Starting from scratch. go with the manual set up from a 240D. You do have to remove the dash to make it a whole lot easier.
Check the PNP`s these cars come in from time to time. we have a 78 and a 82 with manual set up. saw them yesteday, but someone broke some of the front controls.
I pulled one last yr. just be careful removing stuff. take pictures as you go. the front controls are fradual where they are attached to the main unit. there are two pipes that go through the firewall on the pass side, and one on the drivers side. DS hung me up and I bent it

. be careful.
Don`t remember what I paid, maybe $60.00
also a good time to clean everything, especially the evaperator. gets full of all kinds of crap, dog hair etc....
I would use a parrell flow condensor, more efficient.
Go for it. Don`t let anyone talk you out of it.
Take pictures and post your progress.
Dave morisson has a good write up in the DIY section.
Charlie