I have finised Nav-Meshing the Imperial City Marketplace and it's interior cells. Here is a link please tell me if there is any problems with it. http://www.mediafire.com/download/0namso7tr3o0gdp/Tes4_IC-Navmesh.esp
I will create a spreadsheet in the future so others can claim interiors and keep the whole process clean. Also here is Bethesda's tutorial on Nav-Meshing for people looking to help out! http://www.youtube.com/watch?v=raM9TBZZyQY

I'll give it a try. Do you
I'll give it a try. Do you know of a way of extracting the Nave mesh out of something you have already done?
I was also wondering, If you navmesh interiors now wouldn't they have to be redone when the missing objects are fixed?