Gentlemen,
While we are discussing double rifle mysteries, I have a little Jeffery related mystery of my own.
My 450 No2 is marked Edwinson Green and Sons. It has 28" bbls. The barrels are marked as Krupp just like Rustys double and other Jefferys I have seen. The action too looks just like a Jeffery action. The frond and rear sights are just like the ones I have seen on higher grade Jefferys including the 600 I saw in the flesh and other 600's that I have seen pictures of. Most Jefferys have a particular fit and feel to me when I shoulder them My E.C.G.&S [as it is marked on the bbl flats and the action water table] has this same feel. Jefferys all seem to fit me well.
The matte engraving on the sight rib [both front and rear] matches Jeffery doubles and the engraving on the dolls head is EXACTLY the same as some other Jefferys I have seen.
This rifle has a very nice well figured beautiful piece of wood, and the border engraving is nicer than on any Jeffery marked rifle I have seen, it is very well done.

Here is my theory