Mandau with some unusual motifs

[David]

Originally Posted by asomotif

Circles can also depict a snakes biting its own tail. or 2 snakes biting each others tail. The snake being a form of naga/aso like creature.

The ouroboros (snake biting it's own tail) is a symbol that can be found in ancient Greece and Egypt and a concept that has been described (though i have never seen it depicted) in ancient India. It was picked up and used to a great extent as a European alchemical symbol. I do not believe i have ever seen it used in any Asian or SEA symbolism.
MIchael, i still think that the number of rings would be significant to the meaning of the symbol, so it is possible that the 6-ringed symbol on your one kris has a different talismanic purpose than your 8-ringed example.
There may well be a connection between the circles used on these Moro weapons and the ones on this sheath, but we can only speculate, especially with a symbol such as a circle which is so pervasive throughout all cultures.