Bob, I was thinking of you grabbing something for me. Last year at the Fort Wayne race I picked up some nice antenna tubes and mounts from Phil's tent. They have an aluminum base with about an 8-32 nut on them. I could use 2 of those if you think about it. I don't remember who makes them but they can be mounted on a hull or radio box lid.
For those that need them, Phil's also has some of the best prices around on McCoy plugs.