Here are some pics of the carnage.
One of the cheap bulb sockets. Note there are only two prongs left. There "were" six. One was gone when I removed the lens. I pulled the bulb to check it and broke three off trying to re-install it. The other broke off as I was trying to figure out how to get the socket to stay in the housing... Not gonna happen.

Some of the wiring... drivers side. Passenger side was identical. At least they were consistent.

NOW! This is what I'm thinking. Late model bulb socket. Modify the '56 housing to accept the new style twist in.

The sockets even have the correct color leads coming out of them. Yellow = left, Green = right, brown = tail lights and the black is ground for the socket.

As installed.

Made a rubbing of the housing the lights came from. Not a lot to remove here. A little work with a Dremel and a carbide and the new sockets will drop right in...

The new sockets lock on a plastic post when they are turned into position. I will replicate the post with a 6-32 screw. Drill and tap the housing for the screw and it will work great.
What do you all think? Do it?