Gav, does the handle of the cleaned sword look like the silver has some color to it? I wonder if that might not be a silver/copper alloy, which would account for the reddish-brown color of the patina.
I have some silver Thai swords of similar design where the silver patina turned a really nice, rich, lustrous midnight blue. A smalll polished area looked purely silver, but there is clearly an alloy metal there that caused a rather atypical patina color.
BTW, those two swords must be very troubling for you to keep track of--let me know if you want me to hold them for you.