You're right Pertavu. There's no external difference between MiG-27D and MiG-27M. - MiG-27M (M for модификациями - modified) or Article 32-29 were new build second generation fighter-bomber "Flogger". - MiG-27D (D for доработани - improved) or Article 32-27 were 1st generation fighter-bomber "Flogger" airframes returned to the factory to be upgraded to MiG-27M standard. Though their single NATO designation of "Flogger-J". V.P.