Slider window track part

The photos are from a 1' high 4' long slider, top window section. Two
sections of the window slide on independent tracks. The missing/broken
part is the top L that includes the portion that runs in the track.
These are not house windows but are part of a metal deer blind. No
other specs available at this time (measurements or window maker/model).

Since the ranch is very rural (and parts are a problem) I would like to
get several right and left pieces in as many close to sizes as may be
possible.