Matt,
How comprehensive a map are you looking for? I have started Geo-refrencing old USGS maps to get a rough idea of the lines overlaid on current aerial photography. The attached image is small, sorry. Eventually I will convert the file to kml for Google Earth. Right now it will just be simple lines, but I can also add points and shapes for just about anything on the old maps, ie: structures, place names, schools, etc. I would also like to include detailed drawings overlaid on places of interest, yards, sidings, etc. Everything is approximate, we are dealing with a couple generations of datums and varying surveys, the angles of townlines arequite different in some cases.
I would be happy to add any gps data to this, even scaled sketches can be used as long as there are fixed reference points, idealy over an existing aerial or topo map.
Paul