What are the most steam punk historical knives?

Well, steampunk, as I'm sure you know encompasses a few different sub-genres. There is the very Victorian aesthetic as well as more Western component.

For the first, maybe a small, easily hidden dirk for a gentleman. Perhaps for a lady a tricked out hat-pin that delivers a dose of acid or poison. Alternatively, the Victorians were very enthusiastic about Japanese culture, so even a tanto wouldn't be a stretch.

For the Western end of things, a Bowie is probably the most obvious, but there are even variations there. D-guard Bowies were common among Confederate forces. A more traditional "Arkansas Toothpick" style might work for a frontier scout type character.

Being a steampunk setting, all these options might be enhanced with various fantasy tech like electrification, mechanical action, or other pseudo-science effects like "aetheric shock."

Just some thoughts.

The crazy targe and the pistol sword win it for me. That is straight outta final fantasy as far as comparing an aesthetic to a fantasy franchise goes. The mall ninja in me wishes for them badly

Because it was sort of an offshoot of the "cyberpunk" genre. One of the first steampunk novels, "The Difference Engine" was co-written by William Gibson who helped define the cyberpunk genre.

It was based on the "what if" premise that Charles Babbage actually finished his machine and kicked of the Information Revolution in the middle of the Industrial Revolution.

The early stories also tended to be somewhat dystopian and cynical, a lot like cyberpunk. That's the "punk" part.

Well, it's not a good movie, but Will Smith's "Wild Wild West" is steampunk in terms of the "technology."

SP tech is supposed to be devices that theoretically could have been created in the late 1800 using existing knowledge abd technology. Later, more sci-fi and/or fantasy elements were added, especially if using some of the quack theories of the time, as if they were real. Stuff like aether and phrenology.

Think H.G. Wells tech (who was SP in the actual era, so he is kind of the godfather.)

So in a sense, The Time Machine, 30,000 Leagues Under the Sea, and other adaptations of H.G. Wells novels are "steampunk" movies.

Not as popular, but still fun are othe "punk" genres following the same sort of idea.

Dieselpunk- Early 20th century, stuff like the Mummy movies.

Atomicpunk- Mid-century retro-futurism. Flying cars, big clunky robots, ray guns.

Clockpunk- Renaissance era. I mean, anything DaVinci thought up qualifies for this genre, really.