Huh? They use the most common filter in the world? Use the Ryco Z9. The 200 and 300 used the same shorter filter, but the longer one works on a 200.
There are very few things you could need in a rebuild that are hard to find. The head is really the only possible item, but you can buy them or switch to a 300TDI head. It is a very simple engine and very simple to rebuild. Fix it up and enjoy for another 30 years. It will last forever if maintained properly.

