Currently building a Ming army - thanks for the links (there are not that many around).
Had to create my own 3d-version of artillery. This is a "Great Divine" with 192cm length, should work as a Bombard - though the typical gun would be the Great General at 144cm, on a smaller carriage. For action either the wheels will be dumped or the barrel will be laid upon the ground.
http://schudak.de/tmp/pics/GreatDivineSample.jpgThe wheels are currently under rework. Message me if you want some for your army.