Hi Kiwi (sorry about false start)
Many thanks for your post and the site you pointed me to. From this I have obtained a short history of the 20 B-17s sent to Britain in 1941.
As regards the pic I posted of a flying fortress, it is AM(N) 528. It must have been taken by another aircraft at that time? As to the envelope the glass negative is in, this is interesting.
It is within a brown glass negative envelope, from a collection that was in a RAF box.
The writing is the same hand as others, which include Churchill, Arc Royal, and others. They are all very good images, professional.
So, as to the Urals, this is one mystery of this collection.
But AM(N) 528 arrived in Polebrook 21/4/41 and caught fire on the airport 3/7/41. I am not sure where it flew during these dates.
My most pressing interest is AM(N) 522, which we know crashed during a high level trial 22/6/41. The other pic I posted is of an pilot officer. He has a striking resemblance to Lt Follett W Bradley Jn, who was sent as an USA observer, and the son on Major General Follett Bradley. (He was in charge of delivering lease lend aircrafts to Britain & Russia)
Basically I am trying to tie down the history of this collection, most important who took the photographs??
Any help or pointers gratefully received