OK, I have since sold this car, but to summarize quickly:
The RHS camshaft was starved of oil at one end in one of the camshaft journals. This caused the camshaft to get very stiff and basically destroy the timing belt, which in turn damages the head as the valves collide with one of the pistons. I took the head to a machine shop, who basically told me, that by the time I had paid for his work and all the gaskets, I would probably be better off putting in a used lower mileage engine.
So that's what I did. I found an engine with 90,000 miles on Ebay. Paid about $1200, $250 to ship it, and another $300 or so to do the timing belt service while the engine was out. Engine ran great once I had it all back together. But I recommend taking out the engine and gearbox as one unit, because it's very difficult to join and separate them in the car with the V6 engine.
Hope that helps.
Mark