[StarOfTheWest]

Two tricks I have seen to determine authenticity are examining the blade inscription under magnification and checking centering of the motto on the blade.
The motto is supposed to be chemically *etched*, not engraved, any tool marks indicating engraving make it a forgery.
The OCD tendencies of the era will also show in the alignment of the motto.
The letters *must* be centered along the ridge of the blade center.
This is not an easy thing to do apparently, as the forgers have a hard time with this.
Compare where the "e"s line up to the center ridge, at both ends of the inscription.
Also note how well the eagle is fitted into the wood of the grip.
There should be no gaps at all, fit should be perfect.
Your pics are not close enough of the inscription to determine these things.
Because of the high dollar value on SS daggers, forgeries have been made even back in the 1960s.
Good luck!
I hope yours is authentic!