Any interest in a video seminar showing every Model A carburetor?

[alexiskai]

What I don't understand is, why did Holley, and to a lesser extent Zenith, spend so much time faffing around with these cosmetic design changes? It must have cost money to make new masters for the molds. A few internal design changes were pointed out, but most of the iterations shown appear to be internally identical.

The changes in the side vent also don't make sense – isn't that something they could have tested internally to determine what size was optimal?