Thanks, Ade. Some progress and a bit of a set-back, today. The eccentric rod has been made by modifying the rods from the Brassmasters Fowler 4F valve gear etch. The length has been reduced and a pivoted arrangement provided so the rod can fit over the eccentric sheaves allowing the crank axle to be fitted and removed with the valve gear in place. Hinged open: Closed, using a brass wire staple: The set back is losing one of the slide bar mounting plates - the rectangular one seen in the bottom right in the last photo in the previous post. Extensive searches of the work bench and floor have failed to locate the errant part. It's not something I think I could scratch make, with the four small (1.0 x 0.8 mm) rectangular holes. Fortunately, Brassmasters are able to supply a replacement part etch; so a big thank you to them. Con rod next? Dave.