tbirdblog,
These dashes were completely assembled before they were installed into the car. To remove the instrument clusters, etc., while still in the car is possible ...BUT...
Ive had the one in my 55 out and I can tell you it wasn't any fun. I'm 6' 2'', and lying on my back on the floor under the dash, between the seat and the transmission hump, working with a headband light and very tight quarters with long arms, damn near crippled me.
You often can't see the nuts on the panel fasteners past wiring and brackets, and have to go by feel alone. Then, some fasteners you'll need long extensions or flexible extensions to get to. On top of that, many of the bulb clip ends all look the same, so getting the correct bulb back into the correct location (oil light versus turn signal) takes tape labelling, or a good memory.
If I ever have to do it again, I swore that I'd remove the seat from the car, and have a skin full before I started.
Once you have the perimeter fasteners of the instrument panel removed (really just loosened enough to free the entire panel in one piece), most bulbs and wiring can be disconnected from the various instruments with the panel pulled 8 inches or so from the dash, by reaching in behind.
To get an idea of what you're up against, do a Google seach for "57 Thunderbird dash pictures". Scroll through all of the pics until you find one showing the back of a 57 instrument panel, and click to enlargen it. It'll show the small perimeter panel fasteners I referred to.
Again, it is doable, but it isn't any fun. Good Luck!
