Hi Wayne,
Thanks for your observations
Yes, many weapons were left back by the French, during their disastrous way back home. But i have a different feeling about this specific blade exercise ... like it being a formal import, result of some noble or (also) rich owner having ordered it from France, to show signs of wealth, a custom common at the time.
Oh, i was about to second you in surprise about the fixation of the cup being 'screwed' by the outside and 'riveted' by the inside, but i took the sword to the (Portuguese
) sun and discerned some thread in its (half rounded) end.
.