Perhaps you are already aware of this, but the Volcanic pistols in that display are reproductions (in fact, likely just resin castings) - if they were real/original their total value would undoubtedly exceed US$100,000, if not a whole lot more ...
With all due credit to the Staff at Fort Whoop Up, the display is historically inaccurate, since the Volcanic pistol was only made by the Volcanic Repeating Arms Company and then possibly by its successor the New Haven Arms Company (and, in any event, only to chamber the short-lived, caseless "Rocket Ball" ammunition, so far as I am aware, not the metal-cased self contained ammunition which had become the norm by about 1870.)
Also, so far as I am aware, the Volcanic was never made, or marketed, by the Wincester Repeating Arms Company (name change in 1866, from the Henry Repeating Arms Company founded in 1865) so the lable/stencil on the crate is a real giveaway ...
Nobody makes a functional "firing" reproduction that I'm aware of, but there are plenty of non-firing replicas on the market for about US$60-80, if that would suit your purposes Ben (Google "Volcanic Pistol" though that will also turn up numerous hits for the Avon "Volcanic Pistol" Collector Bottle/Decanter ...

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Just make sure that it doesn't run afoul of the Canadian "replica gun" prohibition before you rush off and buy one! - However, I believe that such a replica would be OK ... here is an extract from the relevant page of the CFC website:
To be prohibited as a replica firearm, a device must closely resemble an existing make and model of firearm. If it looks like an antique firearm, as defined by the Criminal Code and Criminal Code Regulations, it is not prohibited.
Link to that page:
http://www.cfc-cafc.gc.ca/info_for-renseignement/factsheets/replica_e.asp