The Air King's can be very nice performers, Mapman, if well restored and/or in good condition, although most of them are not worth a great deal. There are a few very rare plastic (not wood) Air King models, though, that are considered to be important and influential works of industrial design and industrial art. Those particular models, depending on their color and condition, can be worth many thousands or even tens of thousands. Most notably two models from the early 1930's, the 52 and 66, and to a much lesser extent the model 770 from a few years later, and the A-600 from the 1940s.
You can find many pics of those models via a Google images search. I've never seen any of them in person, though, in about 20 years of collecting :-)
Best,
-- Al