I am pretty sure those were used in several Bally games. The specific dimensions may actually be unique to one game or another however that style is used in several. IE: I have had a Bally/Sente SAC system cab that used that bezel turned 90 degrees for a Horizontal monitor. I have also had a Bump 'n Jump with that bezel vertical. Looks like yours is from some vertical game judging from the sticker at the bottom.
Anyway, as to mounting it. See the little rectangular recesses in the face? One at each corner? There is a little tab that hangs out of there to hold the plex filter that sits in the channel around the opening. A screw goes through that tab, through the hole, and into a bracket that bolts under the bolts that hold the tube to the monitor frame. Either dig up the brackets (they are actually 2 long brackets, one for each side) or make up 4 individual brackets out of some scrap metal. If you want some of the factory brackets I am pretty sure I have a set.