It is great to see interest in Indian weapons developing further here on the forum!
In looking at this very interesting piece, the observations on the dorje form pommel are well placed and do of course recall that decorative element on Tibetan ritual items such as the phurba as well as seen on 'parasu' (ritual axe) and 'kartttrika' (ritual chopper). I do believe however that this is an Indian sword and by the hilt, probably either Deccani or Mysori. The blade seems to be of the early khanda type, and the assessment on the date seems reasonably placed c.1800, the blade quite possibly earlier.
The hilt of the sword seems characteristically 'atavistic' in line with many Indian weapons, especially those intended for ceremonial or court purposes, recalling decorative dynamics including 'Tantric' elements (as seen on the Tibetan items) as well as the typical architecturally influenced structure.
The botanical theme of the lower part of the hilt recalls similar hilt guard form as seen on early Pala swords c.10th-13th century (Rawson pp.2 and 9), and the hilt overall carries subtle similarities to Indian dagger forms such as the chilanum.
The hilt on this sword seems to be somewhat associated in style with a number of the forms seen in Robert Elgoods "Hindu Arms and Ritual" though certainly not necessarily by typology as much as by the symbolically structured and brass characteristic.
Looks like a great acquisition!!
Best regards,
Jim