Peglar,
When looking for an answer, I (also) found 12 May 1944 to be worth a better look, without dismissing 7 May in your question.
This website gives quite some B-17 losses in the Usingen/Bad Camberg/Bad Nauheim area on 12 May 1944, with 452nd BG in particular.
Perhaps it gives you a starting point.
Scroll down to bottom:
http://fliegerschicksale.de.tl/12-.-...4-Verluste.htm
Grüss,
Leendert