Steev, I still haven't seen any E-bodies in the yards near Portage. I know there's probably still quite a few lurking around in people's yards and possibly some wrecking yards, but you just need to look down the back roads outside of the City. (Madison)
I just thought of one ('70 R/T SE Challenger), but it's way up north in WI. (Near the Upper Peninsula of MI border with WI.) How motivated are you to find a car? I've known of this one since I was a Freshmen in HS. (5-6 years ago) and I've known a couple people tried to buy it, but he won't budge...typical excuse that he plans on restoring it someday.
I haven't been back to the road lately, but I believe it's still sitting. Let me know if you'd like to pursue it or not. I can give you information as to how to get there from US-41 from the GB area or from Madison. (same route either way.)