There were several lines of such kits from Japan in the late '40s and into the '70s. Find John Buckner here or in the Beginners forum and I'm betting he can tell you everything about it.
I have built a few of kits from those times. There were many converted from CL to RC especially the B-36. "Royal" out of Denver distributed these kits under their label within the United States up to around 1980 or better. John Buckner knows!
I built several Royal RC kits. Rather heavy.
I happen to have one of those DC 6 "Super" kits out there in the barn. 'Gonna build it for CL scale one of these days. The problem for scale is there is little to none effective documentation for CL Scale competition. OTOH, the new rule allowing RC 2.4 for throttles and gear, it should be a winner in the flying phase.
There was a same-line B-36 kit back in the early '70s. I had it in my Hobby Shop in Mt. Prospect, IL. The entire airplane could be assembled into a total airframe with NO glue or clamps and could be held up by the fuse and/or wings. THAT WAS BEFORE ANY LASER CUTTING, VERY MUCH IMPRESSIVE. I saw 2 of them converted to RC flying RC Scale in the Glenview Nats '71 or '72. Forget exactly which.
This machine was built from a CL kit, same style as your DC-6, some 8-10 years ago. It was converted/built for RC. ST. 51 . Flies very well, but landings demand my attention. [
Edited to change NATs dates from '72 to '71 and '73 to '72. The '72 Nats was last Navy Nats and Oshkosh was '73. How could I have made that mistake? I was the AMA's Manpower Director at both '72 and '73. [:@] gitt'en a little old I guess.
Thanks for that info Scot.