1956 Tailgate Latch

[Long Roof]

I need a little help. I am missing some internal pieces from my upper tail gate latch. I think the internal parts must have been removed for some reason.

What I do have is the T handle square shaft and mounting plates. The square shaft that connects to the handle that is supposed to turn something inside the latch.

Anybody have one to sell? Even photos of the internal parts would be a great help. I figured I would probably have to make them anyway.

Thanks