How historically accurate do you feel the depictions of vehicles are from the kit maufacturers in regard to color scheme, turret number etc.? Do you think there are certain manufacturers that are more accurate than others?

This can depend on a great many things...mostly on the subject that is used as the basis of the model more than anything else. If there are photographs from the period of the specific vehicle, then they tend to be pretty accurate. If they are going off museum pieces or fragmentary information, then it can vary widely depending on the sources used.

BIll, I agree with you entirely. I wish that a little more care was taken to produce kits that are based off of photos of actual vehicles in operation and not museum knock offs. My impression is that Dragon seems to lead the way as far as accuracy, but that really just my opinion.