Here's the question before the council today: To swap or not to swap? Actually, I think I've already decided to swap, but I'll give you guys the situation and see what you guys think.
Presently my 280SE with just under 417,000 kms on it is presently using a US quart (roughly 950 ml, though I figure you guys already know that

) of oil every 300 kms. It does spot the driveway, but not enough to justify that kind of consumption. With work being 60 km (one-way) drive, this means I'm putting oil in it rather frequently. I was also having A/C issues, which was why I took it in to the mechanic, since I don't have the tools to do much A/C stuff. I asked them to check on the oil consumption while they had it. He suggests it is likely the valve guides and/or valve stem seals, and says that would very likely require pulling the head, which means much $ in labor. And yes, I would consider doing something like this myself, but I was trying to have the car ready for my trip to KY on 5/26.
Turns out, the guy I sold the engine and transmission out of my wrecked 280SEL hasn't done anything with it yet. The engine out of the 280SEL is in better shape, only using a quart of oil every 1,500-2,000 miles or so. His brother-in-law will do the engine and transmission swap for ~$300USD. All I'd have to do would be to figure out how to transfer the car to the location about 400 miles from where I live. My mechanic told me to jump on the opportunity, and I was thinking it was the way to go anyway. The purist in me is annoyed the car won't have the original engine in it anymore, but I guess I'll get over it.
Assuming I do this, I've realized I also need to make a list of what else should be replaced while the swap is happening due to it being the easiest time to do so. Big Richard, if you've got all the part #s together for the firewall grommets (or even some) could you send them my way? Though that could get interesting for the ones that are RHD specific...
So far on the list:
Motor Mounts
Transmission Mount (or Rear Motor mount, whatever you wish to call it)
Firewall Grommets
Edit: Front Flex Disc
Anything else my fellow W116 scholars can think of?
Or, on the flipside, any rebuttals to the idea of swapping engines instead of repairing?