A'rtnoon all,
Time still very limited, so it's a coffee time dash and go, sorry!!
WW2 - no - circa 1948/49
AOP - no
STOL - yes, of sorts
Glider Tug ??
The other clues seem to fit the Rubik R-18 Kanya ??
Maybe not as I think there's a tail strut that should be visible at that angle, Open House if it is as I gotta go back to the workshop now