Old, Very Well Made, Tiara

OK, don't take away my "guy card" just yet, costume jewelry is a bit out of my normal realm but found this at a little garage sale today. Obviously old and well made. Is five inches in diameter and 3" high at the highest point.
I assume it sat on top of a hair-do and the little loops were for bobby pins.
Going to run it by a friend who is very knowlegable on old jewelry.
Is missing three stones on the very back.