Robert,
When I got my Fox .07 it did not come with a tank. I don't think many new modelers building Scientific kits would convert them to beam mounted. Perhaps if they got the Comet version with the tank, a Scientific kit would work well, albeit a bit fast. I used OK Cubs and a Space Bug Junior for my Scientifics back then.
Berkeley kits... Everyone should have built at least one.

Didn't take Duke long to realize he had bought a "pig in a poke".
Berkeley's saving grace is that they had good plans.
George