1./NSG 9, Ju 87 D-5 Werk Nummer 141010. I don't know the exact code but the Staffel markings were E8 + _ H.
Happe was the observer and his pilot was Uffz. Ewald Kapahnke.
I've written a whole book about NSG 9 which is still available:
Ghost Bombers, the Moonlight War of NSG 9: Luftwaffe Night Attack Operations from Anzio to the Alps (Classic Publications Ltd., Crowborough, 2001) ISBN 1 903223 15 6
There are additions and corrections ot the book on my website
http://www.ghostbombers.com and I would appreciate a scan of your photo of Happe to post there, if possible.
How did you get hold of it?