Wow, there's a 1978 172N with 415 TTAF in there, that's impressive, and also sad. I'd be worried that because it hadn't been used enough you might have issues in that department!
I'm partial to the 172N because I taught in them for over a year and a half. I really enjoyed having the 40-degree flaps(which in normal circumstances aren't really needed). I had a lot of fun in those planes, and there are plenty of junkers and plenty of nice ones also. There's a guy on the same field that had one with the Pen-Yan Aero 180hp upgrade, Power-Flow exhaust, had the 50gal instead of 40 gal, and that thing would move! Definately was a gem of an airplane.
The only true way to find which ones are good or bad is to actually just go out and see them. Make some connections with a mechanic that when you do decide you are going to get one, have that mechanic do a Pre-Buy. ABSOLUTELY make sure you do a Pre-Buy inspection, and a title-lein search on the aircraft. I can't stress that enough. It's something we do every time we buy/sell/broker an aircraft through my company.