I've spent the last few days at the Archives using this reference,
Fiche No. 5970 - 4 Sep. 1939-31 Dec. 1942
5971/01 - 3 Jan. 1943-31 Dec. 1943
5971/02 - 3 Jan. 1943-31 Dec. 1943 (seven images only)
5972 - 1 Jan. 1944-29 Feb. 1944
5973 - March 1944
5974 - April 1944
5975 - May 1944
5976 - June 1944
5977 - July 1944
5978 - August 1944
5979 - September 1944
5980 - October 1944
5981 - November 1944
5982 - December 1944
5983 - Jan. 1945-Mar. 1945
5984 - Additional German records on aircraft from 30 Dec. 1943-June 1944
5985 - RAF Bomber Command battle casualty report listed alphabetically by organization for January 1945 (17 pages or images only). Gives names of RAF BC casualties by unit. Jan. 45 only.
While the above fiche list the British losses and assigns them a 6 digit number, there are no British reports at NARA.
I have spent a little time looking thru the AV, KU, ME, J, etc. reports and have only found reports dealing with American aircraft or American Airmen.
If I can help you with items from NARA or NASM feel free to contact me.
http://forum.12oclockhigh.net/showthread.php?t=15094
Regards,
Mike