[Jim McDougall]

Thoroughly interested in this weapon, I looked further:
Apparantly in South China, where a great deal of foreign influences converged in the regions of Canton, there were forms of Kung Fu which included use of paired edged weapons, usually knives termed 'hudie shuang dao'. These were commonly termed butterfly knives as they were typically encased in pairs but not to be confused with the Filipino folding knife (balisong).

One reference notes that some had a 'long narrow blade that emphasized stabbing" . It was noted that some of these were termed 'red boat' knives having to do with 'Red Boat' (red colored junk) opera troupes who performed as a cover while practicing as subversive revolutionaries covertly, and these kinds of weapons. The illustrated painting is not specifically shown as representing these persons, but to illustrate the variations of paired edged weapons known used by such martial artists.

In any case, during the First Opium War (1839-42) many conflicts were situated in Canton regions. Here we can see the potential for European influences, as seen as mentioned in other cases as the 'butterfly' knife sets with knuckleguard. It would not seem far fetched that these Chinese martial arts weapons might adopt other hilt features (as cast ribbed grips) as well.

While we cannot say specifically that this is one of these Chinese knives, the purpose of this information on possible Chinese association is for the benefit of evaluation by those interested here.