John, the "A" grade had a slim, rather nice looking beaver-tail. I'd post a picture of mine but it has a home-made replacement; probably just what you have except mine's likely uglier. You might try one of the firearm auction sites for a picture or maybe the Lefever collector's site. There are pics is both Walt Snyder's Ithaca book and Bob Elliot's Lefever book if you have access to them.
By the way, if you ever read the magazine "Shooting Sportsman" in which 'The Major' was for many years the monthly last page standard, the Major's only gun was a 20ga Lefever A grade. I think that alone accounts for a lot of the consumer interest in the guns...Geo
