The backup lamps were still an option pre-'66. The basic kit as far as the mounting goes should be that same as what was used on the '55-'59, especially from the description of the mount you give. It's the same as what came in my backup lamp kit. It's basically a momentary normally off switch. I don't think an AD brake light switch (lever activated) will work. You'll need one that has a button on it. I'll see if I can post a pic of mine so you can see what it looks like.
