No pictures...I'm computer illiterate(just ask my wife). I mounted mine on a piece of plywood like you described. Mines pretty thick, maybe 3/4 stuff. I counter sunk the holes for the bolts from the back side and used wingnuts and lock washers on the top. I'd done mine like this originally so it would be portable.
Good thing about these forums is you can learn stuff if ya pay attention. I've had OOOPPPSS! before and cleaning up shot, particularly from carpet ain't no fun. I'd never though about using some kind of attached tray, like a large cookie sheet! Thanks, guys! My wife will be thrilled!
HWD