The wheels are dished.
If this is true and the axles are not tapered or bent such that the spokes are not vertical between axle and ground, you will have a problem. This will cause side thrust on the joints at the hubs which will loosen those joints, and moving with the wheels rotating will make things worse.
This thing will move about 15' once I have the barrel mounted.
It is likely to stay in the same position for a really, really long time.
It is for display only and will not be going into battle.