all i need's an accurate layout of streets, and i really need it to cover south philly in particular. it's amazing--i can get my hands on restaurant reviews for places that served their last customer over a hundred and fifty years ago, no problem, but i can't find a single simple 20th century road map anywhere.
i've googled (philadelphia, map, 1979, south philly, out of print maps, etc), i've hit abe books, i've poked at the salvation army site, i've even hit the rand mcnally site to see if they had an archive. the obvious answer i guess is to drive over to the historical society, but that would be difficult to pull off right now.
otoh, if you have documented evidence that none of the streets in south philly have changed at all from 1979 to now, that would also solve the problem. ;)
[EDIT: thanks for pointing me in the right direction, guys! you're awesome.]