Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

An offset connecting rod on a model such as this probably has little to no effect on its performance,  it would be relying on the bolt to axle disc to keep it more rigid than it should, & wear a bit more laterally on the connecting rod and steam gland than it should. I'd buy this should it come up for sale just for the oddity of it.
A full size engine would/should never have such a configuration.