I see that kind of question a lot. Remember this was in the day of kits, everything was an option left up to the builder. I remember when I first started pattern in 1978, Hanno had just won the worlds withthe Curare, and thus a lot of models I saw at contests had anhedral added to them; Phoenixes, Dirty Dirdys etc etc.
Kinda like adding cantalizers to todays pattern plannes.