Well, there's a find that's definitely relevant to my interests - I've got what I think is the big brother model to yours:
(Top photo above is mine as it sits today; bottom photo taken by the person I bought it from.)
Yours is the first cabaret model I've seen, and it looks as though they used the same lower cube section and a very similar control panel for both it and the full cabinet. Interestingly, yours has the game name painted onto the control panel; mine is generic and doesn't mention a game.
Omni is something of an obsession of mine that I've been trying to dig up more info on for some time now:
https://forums.arcade-museum.com/showthread.php?t=334045 (A few months before buying that one, I was asking for help ID'ing the cabinet from memory)
https://forums.arcade-museum.com/showthread.php?t=355110 (This is the one I ended up buying)
https://forums.arcade-museum.com/showthread.php?t=355012 (Someone else asking for help ID'ing the manufacturer badge; they had the same cabinet that's now mine)
https://forums.arcade-museum.com/showthread.php?t=382867 (Me looking for more info on the cabinet & manufacturer)
One last image: this is the manufacturer's tag on the back of my machine:
Click here for photo of tag; image is too big to embed.
If there's any chance that you could scan and post the paperwork that came with your cabinet, it would be
very much appreciated. I've added in the tags that I set on the other threads to help with finding them in searches; sorry I'm not much more help, but there's not much that I've been able to turn up on the company other than that they were operating out of the City of Orange, California.