Just wanted to follow up on this thread. Got it all back together and running a few weeks ago, after lots of work:
* Rebuilt carb (probably unnecessary, but that was my starting point because it was running rich)
* Completely new #1 cylinder head, including all valves, springs, rods, lifters, etc
* New head gasket on #2 cylinder
* Lots of other things taken apart, cleaned up, lubed, properly torqued, etc
After the first start, the horrifying sight of oil being sprayed everywhere greeted me. Luckily, it was just a loose bolt on the breather cover, one of the few things I hadn't taken apart. Tightened it back up to the proper torque and it ran well with no more leaks.
About a half hour later, the deck drive belt let go... Sigh. If it's not one thing, it's always another. But another belt and more hardware and lubing later and it's running well again.
