Here are some pictures of the bracket. The u part measures 21/64. The u part is not smooth as you can see from the pictures. It has a small step in it. The length of the u part measures 15/16. The back flat part with the holes in it measures 1 15/16 x 1 1/4 in.
Bob from SWISCO responded:
October 21, 2020
How does our 32-012 socket pair match up? Note that the size and shape of the gap that accepts the track is generally the most important dimension here. See what you think.