Looks like a 71-74 Bug shaft with the column lock cut off. Start there and look for an upper column bearing. Should be a 111.953.559A HOWEVER I can't recall if those years had the upper bearing ride on the top of the column lock and if they did then your bearing would be fully custom to have a smaller ID.
You can also use the 62-67 press in bearing (113.415.585A) with a tapered nylon spacer and spring, but that would also be dependent on what size tubing was used for your column tube and I have no idea what TR did for that...