Hi Paul
The original "VECTOR" is 57.5 inch span and 630 sq in, it is a 45 to 51 sized ship, designed in the 1980s, some people have used pipe 40s in them and piped 45s also.
The 40 series of airplanes are smaller and are designed to be the 35 to 40 size, the 40s sized ones are the VECTOR 40 , DREADNOUGHT 40, Tempest 40 and SV-40, the SV-40 looks like a small SV-11. The Vector 40 that I designed and sell plans, Kits, laser cut kits, ARFs, and ARCs are the same plane, we just did a new plan when I worled with John to kit the Vector 40. there are differant iso drawing and things on the Aero Plan than the Brodak kitted one, but they are the same VECTOR 40 plane.
SV stands for " STUNTCRAFT VECTOR (series)" for the new airfoil I developed that is scalable up or down in size.
Regards
Randy