Antique Chinese-style Dagger, Warring States Period

Some time ago, I presented this antique bronze dagger with a green patina, noting that its exact identification was beyond my expertise. Since then, I have been contacted by specialists who have kindly helped me identify it.
It appears to be a Chinese dagger from the Warring States period (-481/-221), but although the patina is very attractive and although I did not notice the coarse casting marks usually found on modern pieces, this would be probably a reproduction, difficult to date (19th century? 20th century?)
I am therefore relisting this dagger, at a price even lower than what I paid for it, and I am selling it as a probable reproduction.
The entire weapon is made from a single piece.
BLADE = it isdouble-edged, and each side features two hollow edges that surround a central ridge.Blade length: 18.5 cm; width at the heel: 3.5cm; thickness at the heel: 3.4 mm
GUARD: It is rounded and decorated with geometric motifs
HANDLE:It is rectangular, divided into two smaller rectangles, and ends in a large, rounded pommel pierced by an oval hole. The decorative motives are difficult to describe. Perhaps stylized plants?
Ref 4Y-12XX    Shipping costs: France €20, Europe €30