Thank you so much for uploading these. They are fascinating. As someone who walks the Humber trails often, I can't get over those Hurricane Hazel pictures.
Regarding the set of pictures which you suggest are of the Flindon Road bridge over the Humber, I think they are in fact what the captions say they are, pictures of the Albion Rd Bridge over the West Branch of the Humber, which is a little farther NW along Albion, approaching old Thistletown. The pictures match the Salmon pictures of the Albion West Branch bridge in the TPL photo archives, and the poured concrete abutments do not match the stone abutments in pictures (past and present) of the Flindon bridge (or Old Albion Rd Bridge, or Musson's Bridge, as it was also called). The trusses are also different.
By the time of Hurricane Hazel, the old Albion truss bridge over the West Branch had been replaced by a concrete bridge, and this is visible in another of your pictures, but it's mislabeled as being of the Weston bridge over the West Branch of the Humber, when in fact it's Albion.
The last of this set of pictures in your collection, of a smaller truss bridge, is a mystery. Could it be a predecessor of that West Branch bridge?
Thanks again for making these available. I appreciate it.