Gavin Leslie mentions it would be simpler to replace the whole unit, than source the bits as he did in the above thread.
I have talked to him a few times eye ball to eye ball.
Here is a link from Bruce Kennedy, swapping in a 240D Type 1 system into his 83 300TD.
Climate control to manual conversion
He mentioned here the 1980 240D was the best yr to pull one from.
Climate Control conversion editorial coming in the near future
I have pulled 4 of these units from 240`s, not really all that difficult to do. you will have to remove the dash. I remove the steering wheel just to give me more room to work. practice at PNP, and remove things as if you are working on Your car. take pictures and document things as you remove them. use some masking tape to lable what wires went where etc...
I have one I took apart to clean and replace the foam on the doors. cleaned out the 30yrs of dirt from the box and Evaperator fins and checked over the Heater core. that is as far as I got then got side tracked to another project. take picture as you go on this one too, there are just a bunch of clips and 3 sections to the box.
Charlie