

this was my old control panel, and as you can see I hinged the top so it opened away from the cabinet like a typical comercial cab.
the top was held down with arcade control panel hold down clamps (or whatever they're called).
the control panel has a full bottom except I cut out access big enough so that you can reach in & up through the coin door and unhook the clamps (this is also how it is typically done on a commercial machine) this access hole did not go out over the sides of the cabinet, so if you looked from underneath the control panel over hang, you would see solid bottom.
for fixing the control panel to the cabinet I added a small piece of 2X4 for support on the inside of the cabinet below where the control panel will sit and I put threaded pieces and I can't think of what they're called now but they have a wood screw like course thread one one side (that side went into the 2x4) and a machine screw 1/4 20 thread on the other. that side went through holes in the bottom inside of my control panel and I bolted it on.
I hope this helps, I'm sorry if I didn't explain it clearly, I wish I had pictures, it worked out well.