The skins are based on Ukrainian Su-15TM aircrafts that are displayed in museums, b/n 15 in Kosice and b/n 41 in Vinnitsa. Su-15TM aircrafts in Ukrainian service were used by 636th Fighter Aviation Regiment of the Air Defence Forces until 1996.
The skinpack is meant to be used with Marco1985's Su-15 mod and to be precise the TM version of the aircraft.