"These guys would rather have $40 royalty each on 0 sales than $2 royalty each on 20,000 sales. Pinheads."
That may be the case but don't discount the fact that there may be collusion with one or more model builders who want exclusive rights to market certain models. If the unauthorized users are knocked out of the competition, the authorized marketers can charge higher prices and pass on a higher royalty to the trademark/copyright owner.
I helped enforce trademarks at a university years ago. We had to constantly act on unauthorized users, usually only securing a written agreement that the mark was used by permission and perhaps a token royalty. But if we didn't police the mark, it would be lost, or worse, we would not be able to stop some manufacturer from using our trademark on something we definitely didn't want our name associated with, such as pornographic products. (It's one reason Barbie spends a lot of time in court.) This appears to be what happened with Union Pacific and the model railroad people. They were satisfied with acknowledgment of trademark and token payment to preserve the mark.
But back to the industry rivalry. Don't be surprised if one model airplane company becomes the authorized distributor and the royalty drops considerably once the competition is out of the way. It is not that unusual.
And pinheads they may be but most of the time they only want to temporarily maim the golden goose, not kill it.
Some good points. Thanks for the info.