Here is a TT Ruckstell I pulled from a field several years ago. I finally got tired of it in storage and decided to pull it apart. I heated up all bolts with a MAPP torch and every one unscrewed! While the spline teeth are heavily corroded, I'm going to try and rebuild the rest.

The gears are bronze and should clean up of all that rust just fine.

I think Burger is right. Before you spend time and money looking for replacement parts try cleaning up what you have.

Based on the right clamshell half (the stock side) that's an early rear end. It has the frequently discussed bead at the axle tube. Very neat! What are you gonna do with it once you get it cleaned up?

P.S. Be sure to count the ring gear teeth to determine whether it's a high speed or low speed set of gears.

It is a low speed rear. There are 4 teeth on the worm.

Yes just counted the teeth on the large ring - 29 so it is a low speed. I do have a high speed set so I will probably swap them out.
Years ago I had a TT but let it go. I've been acquiring parts, running gear (no block) and I will probably rebuild this axle and install the Ruckstell in place of the axle currently on my frame. (That axle also has a high speed gear set)