BoomLover,
I hope I'm not also misreading your preceding post, but scope out the first page of this thread; our compadre and master wood crafter who hails from the tall T has already completed this build, and the outcome of his labors has as usual, resulted in another superb model.
Boom J,
I took a small dowel and actually tried to lever the large wheel on my model. Going between spokes and resting the end of the makeshift trail spike on top of the rail that the small wheel sits on, I could make the gun roll. It was awkward at best and very slow. In a full scale gun I have to imagine it would have been very hard on the wooden spokes. If you were in a hurry to shoot it doesn't seem that it would be practical.
Zulu
I think you've got to be right in these observations, Zulu; on a full scale carriage, how akward would it be trying to gain purchase somewhere on the body of the carriage with the front of the handspike, in order to push against a spoke and rotate the wheel forward? As far as the stress put on the spokes go, I don't think it would take all that long a time before the spokes could hohestly be described as 'casualties of war'.