First:
"who makes WWII RC plane kits that are EXACTLY scale?"
-and-
"I want a perfect miniature (not talking about small details) but the overall silhouette of the aircraft."
Don't make sense. You want a perfect miniature, but the small details don't matter?
Second, I doubt any RC manu makes a perfect scale model (at least in kit form) that meets you're WWI needs. RC planes always have to make sacrifices, as Aerodynamics don't scale perfectly. Every RC plane I've ever seen has at least some "stand-off" built into it. That said, the advent of modern electric power systems means that if you care more about scale looks than sound, you can go with smaller,more easily hidden electric power-plants.
First, I've seen kits in the past that come very close to exact scale, if not matching pretty much dead-nuts on.
I used to have a stack of RC Airplane magazines back in the day. Seems to me Yellow Aircraft and Nick Ziroli would have fit my
needs back then.
Second, yes I want a perfect miniature, but I realize I'll have to make/Find small parts myself.
That's what I meant.