Signature of Luftwaffe KC Recipient 'Otto Engel'

In a very good condition a original signature on a postwar picture of Otto Engel.Leutnant Otto Engel earned the Knight's Cross of the Iron Cross on February 28, 1945 as Leutnant und Flugzeugführer in the 5. Staffel/ Kampfgeschwader 53 'Legion Condor'.The picture comes with a letter of Otto.