Getting there. About to head back outside now that the rain's done and finish blasting the frame. Hoping to get all that crap cleaned up, load glass beads into the blaster and get started on the aluminum parts.
Pulled the valves out on Saturday. A quick tap of the hammer and the exhaust valves released themselves. Despite all the junk and carbon, the valves and seats look to be in decent shape. Valve guides are definitely in useable shape. I will check the springs against the FSM specs, but I am planning to do a set of rings, hone, lap the valves and slap it back together and see what happens.
I have done quite a bit of browsing, but have only been able to find rings for overbore cylinders for these particular motors. If I cant find the correct rings, my most reasonable option will be to send out my jug to David at XLint to swap out for a bored cylinder, and pick up a set of rings to match.