Hi Tiki3, A nice barrel - with an authentic carriage it would make an impressive display in any den or lounge.
Firstly without a "hands on" inspection I would not say whether or not it is a reproduction - though I suspect that it is original - if original then it would present far better with an aged patina rather than a modern paint finish.
I believe that it is British made, the calibre is for a 1pr - such a small piece is either a very small deck gun or more likely a swivel gun - both quite useful for signaling etc. I'm fairly certain that it does not follow a set naval pattern, rather it is a generic pattern produced commercially for use by anyone, as it has a plain crown only with no royal cypher or govt marks. If original I would tend to ascribe a date range of 1820 - 1850, its not an exact science but the combination of its profile, the 3 rings at the muzzle, the trunnion shoulders & cascabel loop lean me towards the later decades of the muzzle loading ordnance era.
Adrian