Almost finished -
I had a few snafu's pop up, as most probably do. The integrated sound of the mounted pc didn't work (I never tested the sound), so I went to the local parts house and bought a cheapo $5 pci soundcard. This was fine, but since the damn thing stuck out so high on the board it hit the bottom of the lcd. I had to lower the entire wood plank everything was mounted into, and it *just* cleared the power strip mounted on the very bottom of that side. Also, the green input jack on the new card for the speakers ran right into the monitor support rail I glued in place.

So... I had to add 2 additional support rails behind the pc to bring it out from the wall a bit. Then I had problems getting this new sound card to work, as trying to disable the integrated one wasn't as intuitive as it could have been. But, persistence prevailed.
It would have been really nice to have cut holes for the speakers and fan before all the staining/polyurethane, but I wasn't sure where exactly where everything was going to fit. I ended up sandwiching the pieces between 2 large pieces of mdf and drilling large holes in a pattern with a steel template, but some holes are ragged looking where the finishing chipped off or shredded. I used a dark brown furniture touch-up marker to mask some of the damage, but ended up with a round black speaker grill to cover up the fan, and will need to find similar rectangular grill covers for the speakers. Any ideas on where I might find these?
Next, all the wiring. This was cumbersome, esp. with lit buttons. I need to take notes on neat wiring. I'm amazed at how clean the guts of some of the projects posted here are.
Then, a small heart attack. After all the wiring was complete, I plugged everything in and flipped the switch... buttons lit up.. pc started up.. and seconds later zap. Power down. Nothing. I had set the pc in the bios to start up upon power failure, but it wouldn't recover when I flipped the power strip on and off like it had previously. Luckily, when I wired a microswitch to the the mobo power it came back. Not sure why this happened, but it could have been the plugging in of the i-pac, both TT2s, and a wireless mouse before powering up.
Compiled mame .140 with the hi score/no nag diffs. Took a few tries to get it right.
Glass has been ordered, and will be in Monday. I ordered a light grey tint, so I'll probably have to up the contrast/brightness of the lcd.
I couldn't get either spinner working in mame, but I didn't play with the settings too much yet. They are both masters, which apparently means they both use x-axis. With an additional usb mouse plugged in, maybe that's why? I need to do some more reading.