I think the context of the heraldic theme is likely, as suggested, Batavian, that is the components in the motif are consistent with the lion, phrygian cap and arrows seen in variations.
That it is naval is of course quite likely in the sense that the Dutch East India Company was primary to Dutch trade and the officers of the vessels that carried that trade wore many variations of currently popular sword forms of the times.
Aylward (1945, p. 57, "The Small Sword in England" well describes the Dutch favor of Chinese styling in swords, with the term 'chinoiserie describing mostly decorative motif (which often included Japanese 'shakudo' in the collective 'oriental' themes and metal work).
In the early 17th century, as Aylward describes, swords were made in the far east for the VOC (Dutch East India Co.) from c. 1710-50, and the term 'Tonquinese' used associating the Dutch factory in N. Vietnam.
This factory was however closed in 1707, so the presumption gave the term.
Aylward suggests that most 'Tonquinese' swords were probably produced in Peking, and afterwards "...the Company brought over some Chinese workmen to Europe, who produced in Amsterdam hilts of similar character which were fitted for blades made in Holland or Solingen".
As this hilt has a strong resemblance to those of Chinese 'jian' swords, I would suggest this is done in that manner, and as noted, probably in latter 18th century in accord with the heraldic theme in the guard,.
On a side note, on the term 'pillow sword', which is a well placed observation here on the form of this sword, I found an interesting entry in,
" Some Facts Concerning Sword Hilts at Hoorn Around the Year 1650"
1970, R.S.F. van der Sloot & J.B. Kist (p.13).
noting that the earliest specimens of these were c. 1616 and in a Swedish inventory of c. 1655, these swords were actually termed 'walking swords'.
Whether or not these were ever placed under a pillow is anybody's guess,but the idea was it was a defensive sword.....which indeed was important whether walking or sleeping
