MkIV had redesigned Vagabond style cowling, front mounted radiators, fiberglass wing tanks, Matco hydraulic disk brakes and wheels, Maule tailwheel with 11/2" tailspring, offset was taken out of fin, offset front mounting taken out of stabiliser! Steel tubing dorsal, belly, and side stringers. External Baggage Locker. Ser #'s 900D to around 1550D.
Editors note: Different literature from Avid gives different data for the same aircraft. None is dated so it's hard to determine what's current and what's outdated.