Fernando,
You are most modest, and your knowledge is more than you will admit, given the remarkable weapons you seem to find these past years!!!
I am of the impression that the pata, as well as the katar are both in degree associated with the Marathas and their associations in trade with the Portuguese . While as indicated, there were certain instances of captured blades, there were a great number of blades of considerable length that would exceed the reach of most rapiers acquired in trade from Venice and Portugal. These early examples were from late 15th early 16th century presumably though most profound evidence seems of 17th c.
Many early examples of katar seem to be fashioned from either cut down or broken European sword blades, of course mounted in the same transverse grip hilt used in the gauntlet hilt of the pata. Although the katar is typically thought of as a punch or thrust dagger, it is known that it was used more typically in the same slashing cuts employed with the pata, though of course in closer quarters. It remains unclear whether these weapons developed concurrently or progressively from one or the other.
Bill's example shown here seems to be quite battleworthy and from the photos appears quite likely 18th c. Highly flexible broadsword blades were favored for the slashing cuts, and seem to contradict the presumption that the pata was used as a lance type thrusting weapon.
Nice fighting example Bill !!
All best regards,
Jim