Thanks Colin, John, Harvey and Guy232 for your kind efforts to answer my questions.
I think that the Model 3 cart is clearly the winner over the K213 cart. The dimensional details and photos were very helpful in solidifying my decision.
Although it probably seems sacrilegious, I'm going to strip the Tektronix's blue and off-white vinyl finish and have the parts shot with textured Polane-T, matching IBM's traditional creme white and black finishes.
Tom in SLC