My condolences on the passing of your grandfather.
The stockman on the left may be a Camillus, or Western, but I'm leaning Camillus. The barlow at No. 2 looks like a Colonial. The last barlow could be Imperial, could also be japanese, hard to tell.
I'm thinking around 1960-1970 vintage, maybe a little earlier. The first one, the stockman, has a solid bolster construction. The others look to have some form of stamped shell construction (thin metal stamped in the shape of a hollow bolster or cover.) They do not have much collector value, but as a sentimental piece that your grandfather owned/carried, they are priceless to you, I would imagine. They would make excellent user knives.