NO... I've made a mame arcade cab for my gameroom, but i want to put it in my office. I've printed my company's logo and "branded" my cabinet but I think it would be Really cool to display it onscreen too.
This is not for commercial use etc.

Just use a frontend and give it your company's logo as a theme, I suppose.
This would potentially be the easiest and the most.. 'modest' choice. Having your company's logo prominantly displayed on the screen between game selections as part of a skin makes it clear that it's provided by your business to your employees for their enjoyment and well-being. Inserting it as a splash before every single game launched on the system would almost imply that your company had something to do with the game's production. Though most people would easily be able to tell you simply branded the system to fit in with the corporate image and/or culture.
I've set up 4 cabinets at my office, the nag screen is removed and there isn't any real side-art on them other than stickers employees put on them from time to time. Just the company logo replacing the hyperspin intro sequence (HS is the front end on all of them) and the nag screens are removed so it just goes as seamlessly as possible into the games.
I also made it a point to include a 'Powered by MAME(tm) and Hyperspin' textline at the bottom of the screen during game selection. I've always felt it important that if you were using something created by someone else in a degree such as having an arcade cabinet outside a home, that it was important that people using it would know full well that while you did some of the work to get it all together, you didn't do it alone.
Epic rambling aside, Just remove the nag screen and put your company's branding on the front-end's skin.