So the "easy" gasket to replace was supposed to be the cam cover gasket. The cam cover is held on by 3 hex bolts and can be removed without removing anything else (unheard of in the Esprit engine). The problem was that the gasket was not only leak-free, but was also virtually welded to the surfaces it was lying between. I could have removed the hex bolts and driven it for 3 years without a leak. When I pried off the cover, the gasket shredded itself - half sticking to the head and half sticking to the cam cover. 2 hours of meticulous scraping with a razor and WD40 got both surfaces clean -> new gasket in, life is good.
The "hard" to replace gasket came off ridiculously easy, new O-ring slipped right in, leak is stopped. Now I have a rattling heat shield somewhere, but that will be another challenge for another day
