Thought I posted a reply earlier?
There is also what looks like a plate with 4 holes centrally on the base on the flywheel side, this would have been an ideal place to mount a feed pump that could have been driven by the flywheel eccentric, you quite often see them at the opposite end of the crankshaft to the cylinder?
If it did do the valve then it would just need some simple levers and links to transfer the movement under the engine and up to the yoke on the other side.
It's in a folder titled "future projects" so is a possibility. I have fancied doing a cane crushing mill for some time and the six column beam engine driven ones are quite common but this one took my eye. There is also one with a horizontal engine and another "A frame type where the far end of the crankshaft is supported by a wall and rolls on the other side.
This one will probably come before the cane mill