John,
Here are the settings using dimensions from the engine and the modified valve gear from an actual working engine.


Here are a couple of photos of the gear as installed. There seem to be some issues that limit the movement of the radius rod. in forward the radius rod hits the conjugating gear link in reverse it is constrained by the bracket for the slide bars that I have already cut back as far as I can to make more clearance.
I think that the return crank radius in the calc will also cause a clash between the expansion link with its mounting bracket!


Thanks for helping with this:)