The Wisbech Rail Reopening Campaign has a photostream on Flickr here.
This includes a set of photographs of the line from March to Wisbech.
A superb collection of archive photographs of the line can be viewed on Flickr here.
Some photographs of the line:
Wisbech Weasenham Lane Level Crossing looking towards March
March Whitemoor Junction. Line to Wisbech straight ahead. March station route under camera to right.
March station left centre with Peterborough to Ely line running from right to left. Line from Wisbech and Whitemoor Yard in foreground.