Very cool...I ran across those videos a few weeks ago.
Closest to a shootable Volcanic as one will get today...but, keep in mind the original Volcanic pistol & rifle did not use metallic cartridges. I believe it was called a "Rocketball" cartridge, which was essentially a hollow-based conical bullet having a small charge of BP & a cap fitted into the base. The ammunition was found "lacking" & this kept the Volcanic from being a big hit...
Regards,
Slim