Hans Schuh wrote a bio based on Nordmann's
Feldpostbriefe which appeared in
Luftwaffen Revue. The 1111th sortie was a date in August 44. I thought the promotion to Mjr. was posthumous, but looking at one of Schuh's images he's captioned it as "
Major Nordmann nach Rückkehr von seinem 1111. Feindflug.."
FWIW two views of Nordmann returning from the milestone sortie
here