You are probably going about it the right way just planning on getting the parts you need from the yard. I just did the 240D engine and LarryBible has recently done a 300D. He had some comments about either sleeves or pistons being hard to come by for the 5 cyl turbo engine if you have to replace either of these - I don't remember exactly. Consider yourself lucky to have a parts yard close by. Take your time and find a good, trustworthy machine shop where you can go in there and talk to the guys actually doing the work, if necessary and you will be fine. I replaced four sleeves along with four piston "kits" for $800 - machine shop and parts - which I thought was pretty good.

__________________
Jim