General Aviation News out of tacoma WA is another place for airplane ads. Also the Flyer outa So Calif, and I believe there are a couple Aviator publications (as in Southern Aviator). Anchorage Daily News is another one. Some or all can be accessed online. Don't forget to check bulletin boards at the local FBO or airport eatery.

Eric

Keith, I'm curious about the O-235 in your Champ. I've seen some 7AC that had 85's or 90's in them, they were "converted" to 7BC,7DC,7CCM, or whatever as a means of getting the bigger engine approved. Not too sure what all that entailed other than some paper & re-stamping the airframe data plate.
I've seen a Champ or two with an O-235, but never talked to the owners about the paper trail. Was it an STC'd mod, field approval, or ?? Seems like it'd make for a fun and affordable airplane.

Eric