The British Air Operational Watch reports don't seem to mention KG 51 at all on any of the January or February Steinbock raids, meaning the Y-Service picked up nothing to identify them. Not until on 21/22 February was there traffic from an "unidentified unit", including aircraft "G", DQ+XV and DQ+XW, the latter two:
"identified as Me 410's, operated with Orly. Previous history shows these a/c to be connected with Orly and not with V./KG 2. It is suggested that the unit is equipped with Me 410's and located at Orly."