Would be interested in a REAL score board?
It was used as a prop in an upcoming movie (starring Canning Tatum), but it is a really, fully functioning scoreboard, complete with control panel.
Let me know and I'll get you some pics.
And it DOES have a super loud buzzer on it.
You can even swap out the names of the 2 teams, and there is a smaller scoreboard that goes with it that shows "KO's" but could be used to show rounds, or something like that.