have a chance to buy one for $500 and wondering about the reliability. this one has been completely refinished and the parts and barrel look great. parkerized and new wood. barrel is 18". also comes with two extra barrels. both 28". at first i thought this was a new shotgun but i know they stopped making them in 1968 and parts are hard to get. i guess i'm wondering if it would be worth it. any help would be appericiated. thanks