Just look for scoreboard.res which is usually located in the resource/ui folder and copy/paste it into another HUD in the same location. Depending on fonts & colors that the HUD you are copying it from is using, you might need to tinker a bit more than that by adding color/font definitions in your clientscheme (most modern huds split these up in separate files nowadays).
Alternatively, if you are using Hypnotize's updated version of this hud there should be a 12v12 scoreboard in here.
https://github.com/Hypnootize/Rads-Hud/tree/master/resource/ui
https://github.com/Hypnootize/Rads-Hud/blob/master/resource/ui/ScoreBoard_12v12.res
Rename ScoreBoard_12v12.res to Scoreboard.res and you should be good to go
Also:
https://www.teamfortress.tv/19073/hud-editing-short-questions-quick-answers