You are right buoymaker. As an example.....the speedway 12 circuit harness at $186 would need a column connector kit at $10. Most of which you would not use, Just the mater to one of the included column connectors. Both items would be free ship. I could not find just the mate being sold. Of course, any 7/8 pin connector pair can be used or hard wire.
You and Kent are right. I've done a lot of wiring sitting in the seat and a lot with the seat out. Thankfully not much to do on a 51. I've only done TF and up....and other brands of trucks/cars. In general, switches are wired hanging, then installed in dash. Gauges may be mostly mechanical. I usually wire of gauges on my lap with steering wheel removed. Some of this depends on the vehicle. Doing a 1957 Willys truck right now.