I built one of these many moons ago. Nice little plane. Mine flew quite well.
I still have it buried in the basement somewhere.

The plans show 1.5 inches of dihedral per panel. 3 inches total.
Thats for the aileron wing. For the non-aileron wing (rudder control)
it shows 2.5 inches per panel. 5 inches total.

I actually built two wings for mine. I built the aileron version
and then thought I might be better off with rudder and got some
balsa and built a non-aileron wing. It flies equally well either way.

This was circa 1985. I do remember it was not very tolerant of wind
but that it did fly quite well.

Mike Hammer