Hi Lew,
It’s a nice katar you have, and I find you are on the save side when you say 18th century.
I have one decorated in the same style – in panels, although the decoration is quite different, and I can’t recall to have seen a decoration on a katar like the one on yours. This doesn’t, of course, mean anything, as there are so many different decorations, both standard and individual ones, so there will always be ‘new’ decorations even if the katar is old

.