Many years ago I did a little work on a lovely Dickson hammer gun made for Captain Trotter (later, Colonel Trotter, after he married into the Rothschild family and was able to purchase a better commission - and many more Dicksons!).
This gun had originally been built as a central fire gun on a pinfire action, by riveting a spacer plate on to the face to house the strikers (frugal fellows, those Scots). The barrels did not have filled notches, as I recall, and were made as central fire barrels from the outset.
You never know what you'll see, if you look at enough of 'em!
