"Do you know of a larger bra that was made, but not known to be worn? "
One for prank, one for charity. Professional NYC prankster Joey Skaggs (crucifix at the Easter parade, dog brothel hoaxes) in response to the Francine Gottfried phenomenon on Wall street bravely strung a massive 50 foot bra across the front of the NY Stock Exchange-actually it was Valentines day 1969 when he did it. he originally designed it for the Statue of Liberty which would've been something.
More recently a gigantic, structurally correct bra was constructed for a world record type event think it was also for a breast cancer awareness project. The exact dimensions escape me...