sweet, i have #32- a low hammer 10- and there are a couple differences
Proofs are the same Birmingham marks - except mine is 10 not 11 and still 12 at the muzzle, same buttplate, same dolls head, the engraving is nearly identical- as are the hammers- the rib lettering on mine is not in a border and mine does not have the lockfast markings
the grades are not always easy to determine - but- this one is mid to upper
i will get the book out later and look for some of these features
you might enjoy a copy--
http://www.clabrough.com/they did restart the serial numbers at least once
not sure what you shoot - but I found mine shoots a consistent 91/92% pattern with lead fours i will eventually work up a light nice shot load and take it waterfowling