I have an old 4 bolt HP .61 that has the cylinder offset to the left of center, (looking from the front of the engine) not buy much but you can clearly see it.
I believe it was a Frenchman by the name of Desake..? (I think) that first came up with it.

"Apparently" the geometry offers significant benefits in that an increased mechanical advantage is imparted at certain parts of the cycle, and improved thrust angularity. The offset was supposed to add a significant increase in power and torque, and improve economy. Offsetting the crank can be used to advance or retard the timing.