I am an " ex" cannoneer. Thoughts: No cascabel ( very strange) and what about markings? If an original tube, there should be markings on the trunnions, and possibly weight markings near the vent hole and on the muzzle. If none, almost certain it is a modern manufacture tube. Military cannons, even signal ones, were marked. If you see an " arrow", it is the British broad arrow signifying British manufacture and inspection. Secondly, take a good, detailed inspection of the muzzle, is there a " ring" visible? If so, it is a modern manufacture cast around a seamless steel tube....it looks like a modern manufacture turned from a steel blank, if so, look at the trunnions, if not cast " stepped" into the tube, and they are straight into the tube, a modern repro for shooting or display. In any case, I would never use more than 2 oz of Cannon grade blackpowder to discharge....NEVER use FG, FFG, black powder, only " cannon " grade blackpowder, it looks like pellets and not fine powder.
As for the carriage , definitely a repro.