My UAII cabinet has/had a detachable control panel (the cabinet is in pieces right now after a moving mishap).
The control panel was one separate unit. The base is a wooden open top box, the controls are in a board that goes on top and is connected to the box by a hinge.
It connects as follows:

There are 4 l brackets (red on the diagram) on the inside of the cabinet. 2 on each side, spaced equally front and back. Where are corresponding holes drilled in the bottom of the control panel box. I put the CP "box" onto the cabinet, Open the hinged top, and put 4 bolts through the holes in the bottom of the box, which in turn go through the holes in the l brackets. I then secure it with wingnuts from underneath, then put in the keyboard drawer. It holds TIGHT, and removes as quickly as you can remove 4 wingnuts. (Read: 30 seconds, maybe.)
The pictures below show the hinged control panel, and the bottom picture shows the wingnuts on the bottom of the panel.


In the bottom picture you can see 3 wires, a Grey wire, and 2 white wires coming down from the control panel. These are 2 DB25s and one DB15 (2 parallel, one monitor cable) that I used for all of the controls.