The numbers inside the yoke are meaningless.
The serial number should be on the bottom of the grip frame along with U.S. Model of 1917.
It should also say "United States Property" on the under side of the barrel.
No, that is not an original front sight. That looks like some kind of aftermarket ramp or ribbed sight. The original is the half-moon style. Do a search for pics of 1917s. You should find plenty of originals to compare to.
It should also have a lanyard ring on the butt.
Those are nice looking older aftermarket target grips. The originals were smooth service style. Again, there should be plenty of pics if you google it.
The eagle and S2 are US proof marks, so yes, the frame was produced during WW1.
Note: If the serial number has been removed from the bottom of the grip frame, you have an illegal gun subject to confiscation and possible prosecution. Return it to the seller ASAP!

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Chris
SWCA #2243 SWHF #292