http://www.drgeorgepc.com/Turtle.html <- This 1776 submarine is the one being built in the Chaltarian workshop
http://www.leonardo-da-vinci-biography.com/images/da-vinci-invention-tank.jpg <- Da Vinci's tank design, the Trammech is very based on this.
http://www.leonardo-da-vinci-biography.com/leonardo-da-vinci-inventions.html <- Other Da Vinci inventions
http://images.wikia.com/deadliestfiction/images/6/63/Minutemen.jpg <- This rather dull-looking picture of some minutemen shows roughly how I imagine the Chaltarian uniform, except that the Chaltarians have colours by region (with the iconic one being russet brown for Flintshire).
The Union uniform would be a little more like that of the British, except that they use cylindrical caps with a brim to the front rather than Tricornes, and the uniform is dark blue and black. I'll work out the uniforms of other nations in the near future.