Just looked at the catalog for the up coming 'Olde Barne" auction. Some really fine things will be sold. Among them is a huge English fowler in percussion. It is an 8 bore with a 48 inch barrel. Looks like quality piece with some mounts in silver. It is Lot Number 873 and will sell on Saturday, April 27 starting at 8:00 AM, EDT US. The gun is described as likely being a market gun. Photo is rather small, but shows a quality piece.
The above is for your benefit and interest, Feltwad. And, thank you for bringing your really 'big' here for us to see.
Dick