Spot on! as they say Kisak!!
Ashoka makes reference to a Victoria & Albert example in Rawson, and notes the NW India attribution about end of 18th early 19th century, to which I completely agree ("The Indian Sword" . P.Rawson, #46, citing number I.M.98-1955).
It would appear that there are at least three, certainly likely more, of this exact hilt, and the Arabesque koftgari of course seems of Mughal style. I think Jens far better at assessing that characteristic, so that is just my guess.
As for the sword overall, the ebay example seems to have a British M1788 light cavalry sabre blade, and I have seen other hybrid sabres of NW India with M1788 sabre blades in other cases. One was a shamshir style hilt, solid steel with Indian tulwar quillons and langets. The blade had koftgari at the forte in similar fashion.
In the British Raj, there was indeed a particular interest in Scottish basket hilts in many regions where some Scottish officers seem to have had these, though the only illustrations I have seen of native officers wearing them were later in the 19th c. In this case, if I recall, it was a Khyber Rifles unit.
I think the influence was far earlier, as suggested here, probably post-Seringapatam.
I think probably one of the most fascinating aspects of collecting the weapons of India are these hybrid forms, not simply tulwars with trade blades, but with regulation military blades that seem to fall outside that group. I have seen tulwars with blued and decorated officers blades and other marked military blades .
Beyond noting these instances of similar type characteristics, it would be hard to see who they were for, but clearly unique and seemingly quite rare.
All best regards,
Jim