Mike,
If you go to
http://www.lesbutler.ip3.co.uk/tony/tonywood.htm you will be able to download Luftwaffe claims lists for various theatres of war. Most of the claims are accompanied with a time so you should be able to, one would assume, cross reference German claims with 445BG losses. That should keep you busy for a while
Also, if you go to
http://www.ww2.dk and click on air units, you will be able to check where almost all Luftwaffe air units were stationed throughout the war. This, coupled with the above, should help further narrow the field.
Hope this helps get you started!
regards
Adam