Having now got North Marsh Road under way I though I would post where the fictitious map came from. I used a copy of the 1946 OS map of Kings Lynn and after quite a bit of 'photoshopping', well Paint.neting I came up with the map for North Marsh Road.

Here are the two maps - First the original Kings Lynn one (flipped) and then the edited North Marsh Road.

I have to say I quite enjoyed trying to create a map that firstly matched the track layout of Wymondham and then one that was plausible with road, bridges etc.