Regarding to Serge Nubret (Ironage site) , Franco was dressed as school girl in 1975 post Olympia party 
I believe that was at Ben Weider's request after Danny Padilla refused to wear it. Danny was excluded from the contest for enraging Ben. Serge said that Franco wore the uniform for sexual activity with Ben but Ben didn't enjoy it because of Franco's hairy rough face beard. Apparently he was looking forward to Danny's smooth face. Funny how Serge mysteriously died just as he was about to publish a tell all book. Jimmy T originally raised the story but it was funny seeing Serge confirm it.