For that extra steampunk touch in the Confed-Union Cold War, give the Confeds a souped-up version of the
Winans Steam Gun. Also, let the confeds be the "submarine power" of this Cold War, like the Soviets were in our Cold War. I.e., the Confeds get souped-up, improved versions of the
Hunley. Maybe ones capable of firing
19th century incendiary rockets at enemy targets, launched semi-vertically from hatches after the submarines surface.
With the steam guns and incendiary rockets, the Confeds will also have steamwagon katyushas ! If you felt TL-191 had some silly Confederate tech-wankery, you ain't seen nothin' yet.
There should be freed and escaped slave resistance cells, supported and financed by the Union to wreck havoc in their great southern enemy. Some confeds would be like Afghan vets, LOL.
Also, lever-action rifles, good as they are, are kind of boring. For that extra steampunk flavour, maybe a cheaper alternative to them, used by some people, would be
harmonica rifles. I don't know about you, but they always struck me as rather steampunky in terms of appearance and
how their mechanism and magazine frame worked. Also, also, air rifles were actually quite advanced in the 19th century, including some repeater versions. Maybe you could use these for stealthy precision-sniping ? Otherwise, the Springfield and the Sharps cartridge rifles would be the Dragunovs or Accuracy International AWM of their day. Add some steampunk accessories, and you might get Victorian or Gilded Age equivalents of "tacticool".
Legend was often referred to, even at the time, as something of a spiritual successor to
The Wild Wild West, sans the espionage genre elements.
A few years ago,
I wrote a brief parody of it and the WWW franchise, with a Persian adventurer/spymaster and his Italian inventor buddy, solving crimes and busting nefarious villains in Renaissance era Europe. The title was the same, but it was a reference to the Persian character's initial disdain for Europe as a less civilised place, the "Wild Wild West" from his Persian perspective.
(And yes, the spoof included a send-up of the 1999 film, giant clockwork scorpion, "younger n' hipper" approach and bad reception as an overproduced remake included. The rap number in period Persian was well-received, though.
)