I'll second the AR type 12 gauge.
Also I’d buy a S&W K frame 6 SHOT revolver in the old thing barreled classic style chambered in 32-20, or 32 HR Mag with a 5-6.5” barrel as a outdoorsmans gun.
I’d buy a Ruger SP101 with a 6 inch light weight barrel in 22 LR, again made for the outdoorsman, not the police or concealed carry market.
I have made seven 6.8 SPC hunting rifles on CZ 527 actions. CZ should do it themselves. Obviously there is a good market for them. Done the way I do them, you get a rifle that weighs under 6 pounds, loaded, including a scope.
I would love a re-introduction of the Krag. The bolt could be set up like the European Krags where the bolt root acts as a 2nd lug and with modern metals and heat treatment, there’s no risk of “weekness”. It would be loved in 30-40, but could be offered in a few other cartridges as well.