Cool Russ,
btw I´m working on MiG-21SPS & 21SPS-K. Only Decal work is left for East Germany (SPS) & Germany (SPS + SPSK).
real 687 is the Number of a MiG-21MF & 463 is a MiG-21SPS-K
East Germany operates the PFM as SPS / SPS-K
MiG-21SPS (Izdeliye 94A; NATO "Fishbed-F") SPS = Sduv Pogranichnovo Sloya ("Boundary Layer Blowing") To avoid confusion with the local "MiG-21PFM" designation given to the modified MiG-21PF (izdeliye 76A), the East German air force redesignated the "real" MiG-21PFM of izdeliye 94A as "MiG-21SPS." MiG-21SPS-K (Izdeliye 94A; NATO "Fishbed-F") K = Kanone ("Cannon") East German designation for MiG-21PFM (Izd. 94A) aircraft wired for using cannon pods.