Re: 1912 New Era
Have you thought about mowers like Dennis? Douglas made some sv single cyl industrials as well, also there are some Norman T300 generators around with what appears to be a flat twin sv.
Just an idea, a bad idea, but retro engineer a pushrod engine, expose the pushrods, rockers, springs? Also, in Oz you may well have had more US gear than Britain had, so you might get Waukeshas, Wisconsins and Maytags.