Hi Folks!
This is an interesting wee piece and I hope I can shed a bit more light on it.
The blade is certainly an C18th piece and perfectly functional. It is difficult to ascertain much about the guard (any chance of a pic of the butterfly shell guard, lower face?), but proportions and form look original, as does the pommel.
The grip appears to be original, and at one time has had a twisted wire wrapping, most likely steel and/or a combination of brass or copper wire.
I would suggest though that the pas d`ane, ricasso and knucklebow are relatively recent additions.
These do not appear to be cast, but soldered or brazed together from stock round section brass, certainly to replicate the basic form of an original style hilt.
C18th smallswords with brass cast hilts were quite common in England, as they were the simplest and least expensive to make and buy. These can be found from c.1680`s onwards and were popular until the late C18th.
In these examples however, the pas d`ane, knucklebow and ricasso are all one piece and usually with more detail in the casting.
Here are a couple of examples of my own recent manufacture, but cast directly from original hilts in either case -
Another giveaway in this case is the form of the ricasso. For this to be primarily functional, it needs to have flat surfaces for the forefinger and thumb to sit against when gripped for use.
I hope that this is helpful towards identification.
All the best,
Macdonald