Many original arcade cabs had a piano hinge on the front edge. Normally there compression latches which were accessible from inside the cabinet through the coin door to unlock the panel.
The hinge idea is nice because you can flip open the CP and make a few quick adjustments without having to hold it or worry about disconnecting any wires. However, the compression latches on the inside make it tough to unlock.
I have often thought about installing some type of twist lock or other mechanism which is accessable without going through the coin door.