Hi,
I think that only the portraits, the De520 photos and some trainers planes photos belonged in origin to the two Flugbuecher...
The rest of the stuff doesn't match toghether at all... there are even some photos taken before the war...
Beside that... it's a WH album with LW photos inside... and it has no onion skin sheets between the album's pages... so... I'd keep my fingers away
