The majority of pinfire "survivors" had badly pitted barrels, due to the corrosive nature of blackpowder. Many pinfires exported to the USA had their barrels internally "cleaned" up by being honed......something I doubt the prospective purchasers were told. It left many barrel walls too thin to pass a British Proof House examination. Anyone intending to use a imported pinfire should check the wall thickness first.
My experiences with pinfires leads me to believe that a greater percentage of bar in wood actions survived conversion to centre-fire. They were usually (but not always) a better quality gun.