Further to my earlier post, might be some ex members of No 1 MPHU (Mobile Photographic Unit) J*hn L**k*tt where are you ?, on here, they were based alongside 17Sqd (
PR) Canberra's hangar where all those funny black boxes were delivered after the Pembroke flights up & down to Gatow had landed (we did Templehoff & Tegel as well), they would no doubt be able to advise what & where it was all about. On the trips to Gatow after taxying in & after refuelling & oiling we were usually towed into the top hangar to unload away from the prying eyes on the watch towers on the far side of the airfield, very clandestine !.