
I don't understand the reason for the opposing axle ends on this model. I can understand that with some models (usually lorries with chassis and separate cab) the axles were inserted at different times during assembly but this seems not the case here.
For me it seems that the red ones were made at a later time and not because Lesney ran out of yellow wheels and kept the assembly line running with red substitutes.
So I'll speculate: Maybe the axle-peening machine was designed for one axle only, and the model had to be switched in the hand to peen the second axle - fastest way would be to turn it 180° between thumb and index finger and then the second axle would be inserted and peened on the other side as on most yellow wheel examples. (But not on all as another worker may turn the model differently and insert both axles from the same side.) And the red wheel GT's were made later on a new machine that was designed to peen both axles simultaneously (probably adjustable for different wheelbases), thus halving the time for this step of production. Could this be the reason or am I wrong? I have to confess that I don't know much about the production techniques used by Lesney.