Doug, interesting piece! Trying to figure out the significance of the pay symbols --
From bottom to top:

3 Gold Nuggets - symbolizing money and/or the Nevada mining riches

3 Blue Conquistador heads - symbolizing searching for gold in the new world? ... or perhaps, Ponce de Leon's men (searching for Fountain of Youth**), as a tie-in to the Tropicana fountains ??? Or if it's supposed to be Cortez, similar to the pic on the early El Cortez chips, there may be an ownership affiliation (both shadow-owned by "the boys" at that time).
**The reason I include Ponce de Leon as an option is that the original owner/builder was Ben Jaffe, formerly of the Fontainebleau in Miami.)

3 Red ??? - can't figure out the red colored symbols. Is it a building or what??

3 Gold Fountains - the iconic fountain in front of the Tropicana in that era (and also prominent on the Trop chips of that time).

3 White Can-Can Girls - symbols for the dancing girls in the Trop's Folies Bergere show, most likely. (Additionally, the graphic is very similar to the dancing girls on the Moulin Rouge chips.)