Unless you know the engine, you'll be jumping out of the frying pan, straight into the fire. Well maintained, loved and cherished TD5's are a wonderful thing. Old, abused, poorly maintained and un cared for TD5's are simply a good way to spend money and increase stress
You mentioned earlier on this page, just how good the original lump was, until it got cam creep. You could remove the cam, fit new white metal bearings (and locktite them in place) and replace the cam, in a comfortable day, with tea and biscuits. With time to spare to look at the bottom end and clean the oil pump. If by some strange reason, the bearing holes are mullered (rare, but can happen), you are part of the way to getting it line bored.
200Tdi's are old, some parts aren't as easy to get hold of as they were. But a rebuild will (as mentioned by Brother Fridge) last you 20 years. By which time you won't have the option of driving anything except your bike. As an aside, in 20 years (which is about as long as I've known you) I will be 78, confined to a very stinky armchair and mumbling about the good old days.