I forgot to take pictures of these last few steps, but if someone wants me to please ask and I will.
The next step was to wire up the coin door to the IPAC-4. I had a little trouble deciding if each coin slot should go to a corresponding player (one coin slot to player 1, one to player 2, etc.). I decided against this, because it seems that most games use common credits, and I didn't want someone to put a coin in the wrong slot and have nothing happen. I wired all of the coin slots together and ran these to player one coin. If a game needs separate coins, the buttons on the control panel will serve that function. This coin door is mostly for looks, but it's nice that it is functional!
next I sliced the end off of an old 5V blackberry charger to power the LED light that I bought for my trackball. Worked like a charm!
I then installed the glass. I got a light grey smoked, tempered, 1/4" glass from a local glass store, and it was perfect! I had installed wear stripping around the edge of the display to "wedge" the glass in...but it turns out it was very difficult (impossible?) to get the glass wedged in there. It actually looked great sitting on top of the weather stripping, so I left it like that! I bought two small brackets and sprayed them black to hold the glass in place at the top, and it is held in place on the bottom by the control panel.
Finally I installed the back panel. After a few coats of paint it was a bit tight so I had to use the old jigsaw and trim it down a bit to fit. I installed the handle and bolts and it worked great!
Here is the end result! Once I get the basement cleaned up and the cab in it's final place, I'll get some better pictures and update the original post with them.
Thanks for all of your help and inspiration!

