Hi John and George,
According to John Krickel's Engine List, the first engine produced by Mel Anderson in 1949 was the Junior Spitfire (045) like in Johns photo. In 1950 Mel came out with the Spitzy .045 with the cast tank below the engine. In 1951 he brought out the Spitzy Senior with the larger tank.
The Cox Space Bug was released in 1952 and the Thermal Hopper and Space Bug Jr. (white tank) in 1953. In 1954 Cox released the Space Bug Jr. with a variety of tank colors.
I believe the RD assembly instructions show the SB Jr, so the RD kits were produced after 1953, but when exactly I don't know since there is no copyright date on the literature. I think I got my dyed balsa version around 1956 or 57, so I surmise that the kits were first introduced between 1953 and 1956.
The instructions in my kit, which has the plain balsa, still refers to the dyed version when they give finishing instructions.
I was able to buy some lemon yellow ink and plan on spraying this on the raw balsa just after I sand all the individual parts. I think you have to do this before any gluing is done since the ink probably won't color the glue the same as the balsa, if at all.
It is going to be an adventure for sure
.
Orv.