Thanks for the tip on removing the pivot pin. I ended up using a very large flat washer resting on two of the 13 mm bolts going into the engine block as supports -- I wasn't comfortable with the idea of using the harmonic balancer, plus I already had it off to replace the front seal.
I agree with you that it is a distressing thought to pull the cylinder head when the engine is apparently running well. However it sounds like you are making an assumption that the cylinder head is already cracked; this may or may not be the case. It could just be the head gasket leaking at this point. The problem (as I see it) is that if you continue to run the engine you greatly increase in the likelihood that the cylinder head *will* be cracked once you remove it.
There are three approaches you can take:
1. Drive it until it drops – meanwhile looking for a good solid used engine to replace yours.
2. While you're still driving your car, start looking for a cheap cylinder head core to rebuild with the assumption that yours is already cracked, and drive it until it drops -- at this point you may have severe corrosion in the cylinder liners due to steam damage, in which case you are *possibly* back to option No. 1, or a complete rebuild. (On my engine the No. 5 cylinder liner was eaten through about one-quarter of the thickness of the cylinder liner at the very top/rear. I'm crossing my fingers that the new head gasket will still seal effectively -- it looks like it should.)
3. Bite the bullet & pull the head now before additional damage has a chance to occur. With 20/20 hindsight, this is what I would have done had I known better at the time. I can make excuses about being a first time diesel owner & not really knowing how well a diesel should run *when it is properly running*, but I hate making excuses. Please learn from my ignorance and save yourself from additional grief & $$$.