In the Osprey book on JG 54, it is said that on 21 May 1943 Ofw Reinheld (sic) Hoffmann scored the only victory of 11./JG 54.
So we have a complete name here, but AFAIK could be Reinhold rather than Reinheld.
There was a Reinhold Hoffmann in JG 54, but he scored kills with 5./JG 54 on the Eastern Front in March and May 1943 (on the 30th). I will be surprised if he flew with 11./JG 54 over Belgium on 21 May 1943.
So... well I think this full name is as reliable as most Osprey books
