'Thanks' Treblig.  I know there are folks who can't say much good about M21s', but I've never been one of them.  You either seem to like them or you don't.
To Geo. Newbern - That's the very same Mr. Zern, George.  I remember reading him when just a kid, which pretty much dates me I'm afraid.  He & Gene Hill were sort of cronies on fishing and hunting trips it seems, and he did write several funny (small format) books which are a hoot also, if you come across them.
I happened to come across the case some years ago through New England Arms, who was handling his sporting estate to some degree.
Robert