Ebob Miniatures has a link on his site for a paper model of Stirling Bridge in 28mm. Ebob makes some really nice Scot Highlander miniatures (including William Wallace), and the English bad guys to fight them.

It's interesting that one of the photos appears to show two Nazgul riding across it. I suppose it could do double duty as Brandywine Bridge.
The instructions are free to download.

