so funny he was using autolites lol
like someone took a nail and just hit it all around.
That's because autolites are garbage. Not being a douchebag or anything, but your buddy is a complete MORON for using autolites. The problem with autolites is the tips break off, and cause EXACTLY what you're describing. Pits/nicks in the pistons, and no noticeable damage to the valves...because the plugs literally fell apart.
If there is damage to the pistons, even if it's only the piston heads, do not reuse the pistons. Sharp edges, nicks, dings, etc. will more than likely cause hotspots, and only cause further damage to the motor. Pretty much what happens with that, is that because the sharp edge of the nick/ding/whatever is thinner than the rest of the piston, that particular spot gets heated up a lot more than the rest of the piston, and causes the air/fuel mixture to ignite before TDC, which pretty much works against the piston and will cause TONS of problems, including MORE engine damage.
I would go ahead and get OEM oversized pistons and hone out the cylinders just to be absolutely safe. Take the head to a machine shop just to make sure everything's kosher, and other than that you should be fine. The bearings/rods/crank should be fine, so total for everything you'd be looking at a few hundred bucks max on the repairs.