Widen your search to include Cleveland and Dayton. I was in Cleveland about 2 months ago and there were a lot of 300 and 420's on every street corner! I almost wish I had some money.... there was one 420 that I would love to have driven home.
Good Luck on your search.... maybe someone in those areas can direct you to a good one.
76 240D (W115) - 550K miles
78 300D (W123) - 200K+ miles