Scott and Alain57,
I think something is messed up in the 390th BG database. There is a way to see a bombardier Charles C Nielsen listed, with 18 missions listed, but it does not show, for example, the 9/25/44 mission. See this link:
http://www.390thspace.com/missions.p...%20Charles%20C
When you search just for the name "Nielsen" on their database you don't find Charles C Nielsen at all, yet he does appear in the mission list above.
You can also compare Nielsen's missions to McKnight's:
http://www.390thspace.com/missions.p...t,%20James%20T
and see some matches on some of the dates and planes. I think perhaps that both men flew primarily pathfinder missions.
Another odd thing about Nielsen is that he is listed as a 2nd Lt on the postwar (1946?) Cook county casualty lists:
https://nara-media-001.s3.amazonaws....8/28-2751a.gif
but as a 1st Lt in the 1947 Chicago Tribune newspaper article cited in his find-a-grave posting:
https://www.newspapers.com/clip/22302819/
Perhaps there was a promotion in process at the time of his death?
I think one error on the 390th site is that they just put the "wrong" "Nielsen" on the 9/25/44 mission, but the inability of just finding Charles C Nielsen listed in the roster is another problem. I will try to contact the site.