Stan, a friend of mine tried putting a more modern 240D engine into an old finbody 110..... He got as far as fabricating engine mounts and fighting the oil filter problem. What you're talking about with separate oil filter is exactly where he halted the operation. Would require tapping ports for hoses in addition to fabricating a flange/plate. That's the point where he gave up.

But the Adenauer 300SD/d idea might not be so bad, especially if the limousine engine bay has room for the oil can filter.

Am not entirely impressed with 5cyl turbo engines. Top speed remains the same. The turbo just provides an acceleration boost. And the differences in having alot more over-engineered components added to the 5 cyl turbo as opposed to the 4 cyl engine are immense. There's nothing wrong with a 220D/115 in original configuration. The 5cyl turbo conversion sounds like a royal hassle to me. In fact, would be better off with gasoline 114 m110 6cyl twincam 280 - stone stock.