Olikara,
Outstanding description of post-Seringpatam southern India, and the situation with the British occupation. Thank you so much for the detail !
It sounds as if the diplomatic efforts of the British favoring Tipu's family and ranking elements of his forces might feasibly have led to a sword, or even a group of such hybrid sabres being fashioned there. While obviously it is unclear how such sabres might have been intended, there does seem to be evidence that the well established Tipu motif, now proudly known by the people there might have been favored in this climate.
Just speculating, and clearly you would have a much better perspective on this possibility with your knowledge and understanding of these events. This truly is a mystery hilt, and becomes more fascinating as we try to discover what it is trying to tell us.
Although your note on the French possibility seems quite plausible (we know that French advisors were there with Haider Ali), the elements of the hilt I have noted (langets, quillon) are distinctly British. The French also had stirrup hilts (also termed D-guard) but these had soundly different form in these. I do know what you are saying on the French thoughts on the M1796, which they termed 'barbaric' in thier use at Waterloo, which was of course some time later.
From your observations on the hilt at the tang aperture, it does seem like a blade was once mounted, and the damage in the missing langet does sound related to the attempts in removing the blade. It was clearly done by someone that was anything but an armourer, and it makes me wonder why it was removed. Could something unfavorable have been on the blade? perhaps an inscription or patriotic slogan, or other? It seems as if the blade was rather brutally removed...but then why wouldnt the entire sword be destroyed?
More questions than answers....but then...the games afoot!!!
All the best,
Jim