Before I start digging a rabbit hole for us to go down, let me say that the model in the OP looks fantastic, and if I were modeling a later era, would be pleased to have one.
I'm confused by the use of "transition era" in this thread. I can understand if it means something different when applied to autos and trucks than what it means in railroad terms. But I am used to thinking of it as the transition from steam to diesel railroad locomotives on Class 1 railroads-overall 1935 (yes, there were some diesel switchers before that) to 1960, or if one prefers shorter, the majority of locomotives being steam to the vast majority being diesel, about 1945-1960.
In my own miniature world, it is 1956. The 1954 IH trucks are over-represented, due to the CMW overstocks some years back, when they were going for $1 each. So I am interested in anything WW2 era through 1956 that does NOT have a 1954 IH cab.