That picture from the history channel doc does have a regular brown 26 lid.
My thoughts exactly on the choco-westerner combo. It actually looks kind of cool that way.
Maybe Weber got it back without the original lid from the former owner or maybe someone was playing musical lids the night before the shoot, who knows? The Westerner was available through the 1960s and it was around 1968-69 that the 26"er lids were reshaped to the flatter lids and there have been flat lid-wood handle Westerners (as pictured). I'm curious if Weber made it into the early '70s?
I also agree about the Westerner being loosely based on the Texas Longhorns logo.