What Blackbird variant is the one at the Kalamazoo Air Zoo? Which one is sitting at the Air Zoo (Kalamazoo Aviation History Museum)? What variant is it?
The Air Zoo refers to it as an SR-71B.  Their image of it shows it in NASA livery as NASA 831. This was originally USAF serial number 61-7956 which was one of two SR-71's built as trainers. 61-7957 was the other and it was destroyed in a crash in 1968.  They were both built as SR-71B's, not A-12's or YF-12's.  

Number 956 was transferred to NASA in 1990 when the AF retired the SR-71's the first time. NASA labeled it as #831.  

There is only one other dual-control trainer and it is an SR-71C, serial number 61-7981 which replaced the destroyed #956.  It was made from parts of the static test model SR-71 and the aft section of YF-12A #06934.  

More info at Habu.org.