It is definitely heavier is section and in actual weight than the later English guns I have handled. It is more like some of the German pieces I have handled of the same period (ca 1750) in both workmanship and overall finish, not quite as nice as a London gun. The fit up and finish is more like a well made Brown Bess than a London or even later Birmingham commercial arm. I attribute that to the provincial nature of its origin. The lock is top quality, and the barrel is well made if not somewhat crude when compared to a later piece. I think that we are seeing what Col Hawker was talking about when he discussed the relative merits of the Birmingham trade vs the London trade. Birmingham individual parts were fine, but the Birmingham workmen lacked the finesse of the London makers when it came to final fit and finish, and perhaps even design. Incidentally, the ca 1760 Pendrills I found reference to were from Wolverhampton.
Mike