I'd say it is a typical 19th C. salute cannon, locally-made one-off. A common characteristic of these is the muzzle-heaviness. They may be the only cannon the maker ever made, so they didn't know how to calculate preponderance and that figure always turned out negative for whatever reason, in their designs.
Salute cannons were the only way civilians could make a "bang" on holidays, back in 19th. C. Loud firecrackers like M80 etc. were not yet available since the pyro formulas involving chlorates and perchlorates had not yet been invented.
The shape of this piece is rather unique, but its function was pretty common.