This is a kit card made to be an accessory for the popular Jeep kit card https://makerworld.com/en/models/223303 I have designed it to match the aesthetics of the Jeep and to function as an add-on.
The tires and cannon should snap in place on the carriage. Use flush cutters to trim off the pieces that hold the parts together.
Here is a one colour print done on a Prusa i3 mk3 with 0.16 layer height and 0.4mm nozzle.
Here is the assembled cannon: