Hello again Chappie.
I've been onto my Airborne obsessive mate 'Bod' and he's got this to say:
"British chap? or a septic? I've never seen that pic before but it does fit the description of what was referred to as 'the island' on the road from Nijmegan to Arnhem somewhere near Driel where the Poles were dropped. That could be Arnhem railway bridge top right a couple of miles downstream of the famous road bridge. The pontoon bridge is obviously a engineer built thing sometime after the fighting maybe even when the British advance eventually liberates Arnhem on 14 April 1945. Yep, found it... on that excellent website you included the link to... (http://www.marketgarden.com/2010/UK/frames.html) "in April 1945 when Holland was liberated, the Canadians first built a double pontoon bridge (Campbell Bridge) on the spot where the ship bridge had been. At the same time the construction of a bailey bridge was started just east of the destroyed road bridge. It was opened on June 8th 1945. Finally in 1950 the rebuilt road bridge was opened again."
Hope that this is helpful, cheers,
Bod" Hope this helps somewhat, no real checking just a quick email exchange but he's normally bloody right.
Good luck again.
Adam.