Just remember restored Parker shotguns have no collector value. So pay only what you would for a shooter. I'd much rather find a well worn gun that shows all its warts and nothing is hidden. Wall thickness: I start getting cautious with anything less than about .022 (personal opinion) and prefer more. Most Parkers were made with more thickness but I have seen several that were originally struck in spots as thin as .020. If they were trying to make a light upland gun they might strike them awfully thin. But if it is a heavier gun and has thin walls it has probably been honed.