Thank you for linking that discussion from some years ago!! Well done on the search..perfect discourse pertaining to this exact character displayed in this amazing tulwar.
As Ariel has well observed those downward angled quillons suggest much earlier hilts, and this example seems almost stylistically aligned with the distinct 'paluoar' of Afghanistan. In the 19th century these regions were regarded as 'India' and as seen in Egerton (1885) these paluoars were included the the tulwar spectrum as far as type.
While in the linked thread some of the examples had what appeared to be machine etched copies of this blade motif, but yours as I noted seems (visually) to resemble acid etched character, and the corrosive activity seems to support that.
After seeing the linked discussion, the three orb symbol comes to mind again, and indeed this was the 'cintamani' which is traditional hallmark represented throughout Central Asian material culture. In India it occurs often as the 'trimurti' and three dots often seen repeated on tulwars, but typically in the north. The 'three' is of course seen symbolically in other cases in religious symbolism, but here, it is the 'cintamani' of Tamerlane, who these people proudly claim their descent from.
Another idea came to mind while writing this, the style of this motif reminds me of that of the Kalash people of Chitral (formerly the Kafirs of Nuristan)
and some of their work. While these people are animists in their religion, and defied conversion to Islam, there were instances of nominal adoption of the Faith, and perhaps these examples might have some connection.
It is an intriguing and exciting example! worthy of much more research...it has great stories to tell no doubt! and a wonderful tribute to your dad, who seems to have had a dynamic sense of adventure.
I think he would be pleased to see this story told
