Fireball; Here is a couple more pictures and I'll try to help, this switch is from my 59 but I think they are the same or close.
The first picture is the hole in the dash notice the two notches top and bottom for indexing the switch.
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This next picture shows the parts. Notice the cup shaped part has two **** poking out these are what match the hole in the dash.
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In the third picture you can see the tab on the back of the cup that indexes to the switch body in a slot right above the teeth of the key. the spring threads on to the switch body and then the cup goes over the spring. Hold these up to the dash compressing the spring, to bring the switch body proud of the dash. and the bezel has two ears on it that enter the front of the switch body one up and one down and then rotate CW a quarter turn.
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Clear as mud??
OOPs I got the second and third picture reversed.