Personally when I look at these older cars, and knowing all the scammers around today. I inspect the 4 torx screws that holds the dash bezel in. Technically my cars body has 128k on it. But the odometer only reads 41k because when my speedo broke I removed one from a junkyard that had feed miles on it. And make sure to see if the title/Carfax has any mileage noted on it. Otherwise, typical rust in trunk, condition of bushings, idle speed. Doesn't hurt to look over the trans cooler lines that run by the coolant tube on the bottom driver side and see how rusty (if at all) they look. I really inspect things to an almost nit picky point when purchasing anything tho unless I go into it knowing what it is and expect problems like I did with my 87 restore..
87 GT (Under Construction)
Madarch Widebody, Kahines tail, 3800SCII.... gonna be fun making threads on those!