I'm with Hawkeye. Don't even think of putting a charge of powder down that tube. Both wheels are falling apart, the axle is held on by one little old screw, the trunnions look to be soldered on,and the seams of the top and bottom barrel halves are indicative of a crude souvenir. Granted, the wheels could be remade, but the barrel should burst with catastrophic results at the first shot.
I bought one somewhat similar at a yard sale, except it was much bigger (but looked to be of remarkably similar design) and instead of a gun tube, it held a bottle of wine. I absolutely couldn't pass it by.