Wow... thanks for all the information. Some of it passes right over my head at this point, but I'll copy it off and save for reference later.

I checked the little pistons under the black screw-tops at the top of the domes and those both move freely, and the big pistons showing through where the air-filters go over also both move freely but slowly, so I'm hoping those are pretty good signs. When I wiggle what I think is the throttle shaft, there is only a very slight bit of play. I'm not knowledgeable enough yet to know what is an OK ammount versus non-acceptable.

This set has been sitting under a hood and in a field for about ten years from what I know (and are CRUSTY!), but I'm hoping I can have them breathing again some day. If not, I'll at least learn quite a lot in the process of trying!