Next on the list was getting everything into the Control Panel. While it may not be difficult to put a quality CP together, I goofed up plenty of things despite a head start (designed beforehand, pre-drilled holes, etc).
HaRuMaN predrilled holes for buttons and joysticks on the control panel and admin panel. Installing the buttons was easy! Just insert the button assembly, screw on the retaining nut and attach the switch. Once you get the hang of it, you can get them all in quickly. The admin panel buttons went in easily as well. I'm using authentic Happ buttons for the 12 CP top buttons, and some fake Happ style buttons for the admin panel. I thought that this CP thing would be a breeze.

Based on the recommendation of many a BYOACer, I mounted the control panel to the batons using some industrial Velcro. It really is nice stuff. Important note: Make sure you stick the strips of Velcro to both surfaces and let them sit separately for a while (maybe overnight?) with some pressure before you put them together. I put the control panel on immediately, and when I tried to take it off again, the Velcro proved stronger than the adhesive, leaving both strips stuck together, attached to the control panel. I had to separate them and wood glue the velcro strip back on the top of the admin panel. It might not be a bad idea to wood glue it to the top of the admin panel right off the bat, particularly since that's the one surface where the glue needs to stick to MDF rather than a melamine surface.

It was then that I realized the depth of my hubris; I had mounted the admin panel wrong, which means my admin buttons were occupying the space meant for my undermounted Happ joysticks. If I would have rotated the admin panel 180 degrees, the admin buttons would have been several inches to the right, completely clearing the joystick. I played around with using extra Happ button retaining nuts, but it looked lame to me and felt way too kludgy.
Having read most of Project Arcade, I remembered that there were other types of buttons than the long Happ pushbuttons. Sanwas snap-in buttons are much shorter, allowing them to be mounted without interfering with the joysticks. I bought a bunch of 30mm Sanwa knockoff buttons. They look different when mounted (convex vs concave, they seemed glossier, slightly different colors, plunger diameter is a bit larger), but for the black buttons on the admin panel, it wouldn't matter much. Besides, having a different style of button might help the start buttons pop more. Later on this revealed another problem (different sized terminals), but that's a problem for another day.

Once I had the correct buttons installed, I could mount the joystick. I bought eight 10-24 by 1-1/2" carriage bolts with matching nuts. I would have liked black carriage bolts, but I couldn't find any. I might track some down online so I don't have shiny silver boltheads on my CP. Or maybe there's a way to paint them? Electrical Tape?
I created my own bootleg mounting template by placing the mounting plate of the Happ competition joystick face down on a piece of paper. I drew a line around the perimeter and marked the bolt holes by putting a pencil through the hole and drawing the hole. I marked the center hole by placing the paper on top of the mounting plate and shining a flashlight up through the center hole. I could then draw a circle that more or less matched the hole in the middle of the plate where the actual joystick goes. I didn't do any routing or anything; with 1/2" melamine and Happ sticks, the sticks are a good length.
I taped my template to the CP and started drilling. Based on Malenko's recommendation, I drilled using a small bit first, then progressively larger. There was some minor chipping of the melamine surface, but the chips were small enough that the bolt head completely covered them.

Once all 8 holes were drilled (4 for each stick), I mounted the stick underneath the CP and wrenched the nuts tightly. I put the stick, dust washer and spacer into the base, then added the square actuator and retaining clip. The clip is hard to attach, but a pair of pliers and some elbow grease got it into place.
Wiring the buttons and the sticks to the Zero Delay encoders was not terribly difficult, but it helps to have a little practice. The Zero Delay encoders come with nice wires with .187 quick disconnects on one end and the other end has a plastic connector which goes right into the board. No need to mess with common ground or any of that stuff. Make sure that you connect the wire to the "Normally Open" terminal with the colored wire and the "Common" terminal with the white one.
Getting the quick disconnnects on the terminal is a bit of a pain the first few times, but if you wiggle it side to side while inserting, it helps quite a bit.

Mistakes I made:
I assumed that the top switch was "up" on the stick, but because it's on the other side of the fulcrum of the lever, the top switch should be connected to "down." Left and Right are likewise switched.
When I replaced the admin panel buttons with fake Sanwas, I didn't realize that they have a different terminal size. They fit .110 quick disconnects. The .187s fit, but they're rather loose. I'd like to think that I'll fix this at some point, but I'm probably lying to myself.
When I made a mistake wiring, I pulled too hard on the quick disconnect while attempting to remove it and pulled the wire right out of the disconnect. Be careful while pulling, folks!
I couldn't find appropriate size screws to attach the encoders to the control panel top, so I velcroed them on. This is a bad idea; it tends to stick to the CP velcro and doesn't hold the encoder firmly to the back. Also, while I don't think that Velcro is conductive, there's a chance that it might do something funky from a circuit standpoint. I bought some feet but haven't put them on yet. The encoders are hanging by the wires, lightly stuck to the Velcro right now.

