I just took out both gauges, ignition switch and the headlight switch as one unit from a '52. I did it all sitting behind the wheel. No crawling under the dash.
1) remove the speaker grill.
2) remove the lightswitch leaving the wires on and push it forward and let it hang there.
3) remove the choke cable.
4) now you can get to all of the nuts on the speedometer.
5) remove the speedometer and push it forward let it hang there.
6) now you can get to all of the nuts on the gauge cluster. Push it back and let it hang there.
7) remove the ignition switch. Push it back and let it hang there.
8) fish the ignition switch down to where you can remove any accessory wires like for the heater.
9) remove the headlight switch, gauge cluster, speedometer, and ignition switch with the wiring harness still attached to everything as a unit.
You will now have easy access to remove the individual wires from each component while sitting in the seat.
I am all but certain that on the assembly line, all of these components were wired to the harness on a bench before the entirety was assembled in the truck in the reverse order which I have described. They did not crawl under the dash is my bet.
What I have described may seem tedious, but I am old and my crawling under dash days are well behind me.
The process was not as difficult or time consuming as it sounds in written form.
