This is a 28mm (1/56th scale) model of a Canadian WW2 Anti Aircraft tank, the "Skink". The Skink was built on the chassis of a Canadian built Grizzly tank; which is essentially an M4A1. The turret holds four x 20mm Polsten auto cannons.
https://en.wikipedia.org/wiki/Skink_anti-aircraft_tank
I crafted the turret using Tinkercad.
I have included two turret options; one with the cannon barrels and a second without the barrels, as dependent on your choice of settings and filament, thin barrels can be fragile. I use 1mm aluminium tubing or even sometimes just segments of the jumbo paperclips to simulate barrels. In the barrel-less option, I have left recesses in the gun mounts to aid securing the added barrels.