Tuxedo is 04, in your save game, so search for Outfit, there are 3 places. First is Override outfit set to 04, next is the standard safehouse hub outfit (the game overwrites if you put the Tux here ), last is UseOverrideOutfit this should be set to 01, to activate.
It's too bad we can't change the actual safehouse hub outfit to Tux, this means you can't just wear the Tux in between missions, it's on all the time. It might be fun to play through a Tux in every scene. I don't see anyway to change the Stats of the Tux