The third variant had a shorter nose moment, no wing fences, a deeper fuselage profile for retracts and a redesigned tail. See first image below. I believe that this variant was the first variant that Kato added to his MK kit line. This was done after he flew it in the 1971 Doylestown Internats.

The April 1974 Model Airplane News did a Field and Bench article by Art Schroeder that reviewed the MK Blue Angel kit. See the second and third images below. Note the slab balsa vertical stabilizer and rudder that stops at the top of the fuselage.