One pair of window hinges used on vintage Silver Streak trailers and Serro Scotty trailers 1969 and later. Also used on many 1968 to 1979 VW Westfalia campers and most likely others. Even used on 1980s trailers from various manufacturers.
Windows are recognizable because they are framed jalousie style windows (one action lifts more than one pane of glass) two or more panes high, with 7" high pieces of glass.
The bottom of the pivot hinge measures 2-1/8" end to end.