Jonathan,

I was considering doing the same with my 1/72 Canonicus class monitor but didn't have the needed space below deck & went with a hacked servo. Combined with the monitor style 4 bladed prop shown in [link=http://walternelson.com/ironclads.pdf]Modeling Civil War Ironclad Ships[/link], you shouldn't have any problem making headway with the Heng Long gearbox setup.

How do you plan to build the hull & casement? I'm looking forward to seeing your thread progress!

Chuck