David, absolutely outstanding points, and well taken! It does make absolute sense that this might have something to do with the Portuguese in India, where serpentine blades with nagan symbolism were quite present. I had been wondering about those cross piercings, which are distinctly of Portuguese fashion and seen on late 16th century swords (of the type of rapier which became copied in Africa's Congo , as seen in Burton).
This rapier has been really puzzling, and while the Masonic possibility presented a rather intriguing and mysterious potential, I still hoped to find more true weapon vintage with it. With your true forensically astute eye, you have found what appears to be 'the smoking element'!! in the hilt. That repair I had not noticed.
Your observations on the combat potential of this weapon are well stated and thought out, and do offer compelling consideration that I also had not thought of.
Rick, your also well placed note on the swept upward asymmetric side of the hilt is very reminiscent of the keris, and adds to the potential for this piece having East Indies provenance as we are observing.
Returning to the Masonic perspective, the only element of this sword that remains curiously non-East Indies or Portuguese in India, is the pineapple pommel, which seems a distinctly 18th century European affectation, as Fearn has noted. I am not aware of the pineapple used as decorative motif on weapons of India, Indonesia or Portugal for that matter, and perhaps evidence of that feature might lend more to better securing possible provenance of this sword.
The game remains afoot gentlemen!!!
Excellent detection and discussion
All the best,
Jim