Continuation and addition to the above Post...A clearer picture of the Sendai Kastane..From
https://sirimunasiha.wordpress.com/a...la-matchlocks/ which as a matter of interest claims the blade is Portuguese !! 
A point I do not disagree with.
The Hasekura stamp or coat of arms (Inverted) between the Vajra Quilons must have been carried out in Manila or at sea on the way to Japan. Perhaps Hasekura saw this as being a Christian countries weapon... Catholic. Thus he had his stamp placed on it (his stamp contains a cross.) and not realizing the disaster awaiting him in Japan where all his family, supporters and friends were to be executed soon after he arrived because of a purge against Christianity.