Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4250089.

This cannon was designed by my grandfather J.W. Mark in the 1980's. I dont' know if he took an exisiting cannon as inspiration or that he designed it from scratch.

He created it in wood and brass. The second image shows the original.

This is a reproduction of that cannon as a 3D-model that is 3D-printable. My printed version is shown in the third image.