Two operators needed

This hardware was installed around 1953 when the house was built. No markings that I can find. One operator (now missing) is for the right side of the frame. The other for the bottom. I believe the missing operator is identical to the other. I don't know if I need new tracks or if the existing ones will work. Many thanks.

The bases are slightly wider on my operators -- 3 3/4" measured from screw to screw, on center. The "rod" is 9".
I think the 39-020 would work for both windows.