$310 is pretty high. I'm guessing someone was sentimental about the ATP and was willing to pay a premium for it.
Man, that auction picture really makes me wish mine was blued from the factory, rather than parked. I just had to get it cerakoted because the parkerizing was looking pretty rough after 36 years. Mine doesn't look bad with a cerakote finish, but you know what they say...happiness is a warm blued gun. (They do say that, don't they?)
It's the shorter one in this pic. I think it has a Bantam stock, and has the heat shields
I ran bird shot,
Buck shot, 2 ball defensive ammo, and some other defensive ammo with 1 large ball and like 3 00 buck pellets in it. Ran flawlessly- action is butter smooth.