Well, I'm done cleaning the exhaust valve and head. Here is a before and after photo, the valve definitely looks and feels much better. Here's what I did:

I took the head to our parts washer at work and cleaned it with Acetone and a nylon brush. I then brought it home and used the dremel with a nylon brush and polishing compound to the area around the valve seat @ 15,000rpm's. I then took the valve itself and used a dremel fine wire polishing brush to remove the build up on the valve. I then put a small amount of polishing compound on the valve face and re-inserted it into the valve head and rotated the valve around to make faces seal better.

So, now it's time for reassembly tonight and a valve adjustment. If the weather is good this weekend here in Ohio I may take it out for a start up.

Thanks for everyone's input, I really appreciate it.

Steve