RE: Oldest RC Company
[link=http://www.guillow.com/]Guillows, since 1926[/link]
You are probably right about Comet, can't find them online
Plus, you asked about RC Companies. Goldberg and Guillows started out as free flight/control line companies, obviously.
For an RC Company I would hazard a guess at TopFlite or SIG but they probably had their origins in control line as well.
Don