As far as the Dominion ammo goes, I think it depends on the caliber. Since they made a number of obscure calibers long after others stopped, they do have some value. If I had a box of 17 .30-40 Krag, I'd not shoot them, as there's still a decent supply of it in other brands, so you don't really need to shoot it.
Dominion was also sold as Cannuck, and Canadian Industries Ltd.
I've got a couple boxes of .43 Spanish, and a bunch of .32 Rimfire in the old Cannuck and Dominion boxes.