For the cranks I used some 1.8mm (approx - I don't know the exact size) copper wire - you can use old spokes, or steel wire, if you don't have copper. I used copper because it's easier to bend and I like copper. If you need to straighten the copper wire you can clamp it in a drill and hold the other end with some pliers - spinning the drill should straighten the wire. Make sure you wear some decent safety gear though, in case the wire slips!
I've included photo's of every step of bending the cranks below. The displacer piece should protrude about 20mm and the other parts protrude about 5mm, no need to be exact though. The displacer part is at 90 degrees to the push rods - this is the best angle for this engine.
The electrical blocks are fitted as you bend the cranks, be careful to make sure that they all point the same way, as you won't be able to access the screws from the viewing window.