Ok, so basically what I was doing was building a 1/4 scale Space Invaders with an actual CRT monitor. Using a GP2X running MAME. That is connected to the monitor and hacked control pad via the GP2X break out board. Custom made switches for the control panel with working coin mech. Coin mech is ugly as hell internally but it allows me to drop tiny washers in for credits (",)
Once I started hacking the monitor, which is portable, I realised I could use the battery box out of it too and make the whole thing battery operated for the novelty of it!
If I ever finish it, I will also make a separate control panel with regular switches so you can hold that as the homemade switches probably wouldn't last all that long...