This is not a working signal cannon, not even close, and it is not an antique. This is a decorative model made in Spain in the 1960s-70s, many types and sizes were made, and all were made to look "antique", many with "dates". This originally would have been mounted on a wooden carriage with fancy stamped metal accents. It is made of a pot-metal alloy colored to look like bronze. Note how the muzzle end reveals that the metal there is very thin - and likewise the barrel walls are also far too thin to be safely functional, even if it was made of bronze or iron. These decorator cannons are very well known to collectors. Whatever you do, never try to fire it, even with just a salute charge, it could become a pipe bomb. Sorry if that is bad news, but better to know what you have, and stay safe.