Well - I did start this thread with "sorry if this is a dumb question"..

I did my testing using only mame in DOS rotating the screen the way I needed it. As far as Game Launcher is concerned I suppose I should have loaded it and tried it out on my setup, but per the GL website, I made some assumptions:
Features
Very flexible. It should run with any command line emulator.
Simple and easy to use interface.
Plays music in the background (MP3s or an audio CD).
Displays screenshots (PNG, PCX, BMP, and JPEG).
Customizable font.
Customizable screen resolution.
Support for vertical (rotated) monitors.
Slight menu animations.
Support for PC joysticks.
I assumed support for rotated monitors meant rotation in any direction, my fault. I didn't count on needing to test a feature, but in the end.....you get out what you put in.
I did contact Dave directly to let him know I will be rotating the monitor physically the way it needs to be, and to thank him for all of his work. My post wasn't meant as a criticism of his work, simply a question regarding a feature.
I'm glad to say that by removing and remounting the monitor I will have a chance to put some tinted plexi in between the monitor and the table top....which I wouldn't have done otherwise. (I have a clear glass top, so I still wanted the tinted monitor effect.)