So isn't it natural to wonder what mustaches some of our local monuments would sport? Well, I'd like to think it is. At least it would explain why I've invested a not-unsubstantial amount of time Google searching "mustaches of the 1960s" and "Prudential Tower."
Construction on the Prudential Tower began in 1960 and was completed in 1964. While this doesn't perfectly align with the debuts of Led Zeppelin, the Rolling Stones, and the like, it does make the 60s/70s rock and roll mustache a fitting choice.
Til next time!