Blockcaver
WKR
The Miroku built 20 & 28 ga M12 repros are nice, very well built shotguns. I’ve owned one of each ga, one called Winchester and the other Browning. Only things I hold against them is weight and barrel lengths at 26” only. The 20 ga weighed about a 1/2 pound more than my 1935 M12 solid rib, weighing in at over 6#14oz and got sold. The 28 ga is even heavier at 7#2oz. Still have it and enjoy shooting clay targets occasionally with it.Good call sending your M12 to Art’s, probably no place knows them better these days.
Now that the BPS is discontinued if I had to buy a new pump gun an Ithaca would probably be my only consideration.
But before doing that I’d be much more likely to hunt down an old Ithaca, a Remington M31 or M17, or another M12. If you wanted another M12 the late production Miroku M12s are super nice and probably your best chance at finding a new or nearly new gun.
The actions are very slick, but trigger pull is a tad heavy at over 6#s on them, but crisp.
I’d find an original in 20 ga with a 28” modified choke, either solid rib or plain barrel if I was looking. 16 ga is great but there is not really anything but hunting ammo readily available for them, and non tox is very scarce. No issue if you reload.