Radu My Friend!
Yes, it is hussars sabre (Polska szabla husarska) from the best period, second half of 17th century, and it is from National Museum
The experts consider, there are three super b, extra perfect known hussars sabres in Poland - this is one of them - with excellent proportion (that's what experts and sabres lovers are saying about this beauty). Made by Lvov's (Lviv's) Ormians, with beautiful niello work, with thumb ring, the blade with two fullers and an inscription "IESVS MARIA IOZEF DEVS SPES MEA".
I can make some detail photos for you, just let me know (via email
wolviex@poczta.onet.pl 
)
Andrew: sorry about digression in your topic
and many thanks for bringing my avatar to live.
Regards