Welcome to AAPK, JwJ!
The Barlow style Remington looks to me like it might have been manufactured in the 1940's. The tang stamp comes from a time after Remington sold their knife manufacturing to PAL Blade company, and contracted their knives made by other firms. The bolsters appear to be steel, as silvered nickel was unavailable during wartime.
Others may correct me on the date - I am just guessing. Either way, it is a beautiful knife, although with too much wear to have collector value.
Of course, I am sure that the sentimental value far outweighs any monetary value to you.
The two-blade Congress pattern is another beauty! I do not know the pattern number or the year, but it was made to be a fancier, more gentlemanly knife than the Barlow The handles are either Ivory, or (more likely) French Ivory.
French Ivory is a faux ivory made of celluloid. Celluloid is potentially damaging to a knife when it begins to break down, but this type tends to be more stable. It could very well last another hundred years. As a precaution though I would recommend that you store the two knives separately. That way if the celluloid ever does outgass, it will only damage the one knife and not both. Store it someway that is open to the air, yet always out of direct sunlight.
Again, those are beautiful old knives. Thank you for sharing them! I hope that they always bring you fond memories of your father ever time you see and handle them!