Hi, I'm building a Jeannie Deans and have hit a snag assembling the valve gear. It seems to be impossible to assemble the Joy valve gear[ which is press fitted together] onto the engine. Because the big ends aren't split the connecting rods have to be assembled onto the wheels first and then the whole thing somehow fitted to the engine. The con rod/ valve gear assembly somehow has to go through the motion plates.. Anybody made one of these?