Generally speaking the element of the crossguard that extends to cover the back of the hand perpendicular to the arms of the cross guard were not seen until around the time of the Renaissance, the Renaissance being broadly defined as a period from the 1300s through to the 1600s.
The best way to date an object is to obtain the services of a metallographer, that will give a definitive answer.
My guess would be that the cross guard is from the 1500s, but I must stress, italicize and underline that this is just a guess.
A little Indian brave who before he was ten/played war games inthe woods with his Indian friends/& he built a dream that when he grew up/he would be a Fierce Warrior Indian Chief
Many moons passed & for the boy the dream grew strong until tomorrow he would sing his first war song/& fight his first battle/but something went wrong
Suprise attack killed him in his sleep that night
And so castles made of sand/melt into the sea/eventually