One very similar is the one of this set,
"arabian nomads", which I happened to have, in my
Portuguese days 
... But it wasn't exactly the same knife. The shape of the blade was very alike, though, very pointy ... Those pots were great! I hope to get them again, some day!
Uhm, sorry, ... Getting off topic with such a simple subject, what a shame! ... The knife you showed, from 3409 "City Defence" (acc. to Collectobil.com) is like this:
o--(---
more symmetrical
however
than I could show here ...
and the one of 3585 is more like this:
v--|---
The knife you found may be thought to have been (generaly) replaced by the common dagger that is now found in many sets, that I first saw with the black figure of set
3794.
I agree that the old knights dagger is quite more like out of a Shakespeare play

G.--
