RE: Club ED
I have three Hunters, I'm pretty sure they are all the same bore and stroke, but the first model is taller due to a longer conrod and cylinder.
SeriesI has a finned head and tall cam turned cylinder (has a bulged section for the transfer, long prop driver.
Series II has a silid head, short cylindrical cylinder, long prop driver.
Series III has a green solid head, short clinder and short green propdriver, green spinner (green parts were shared with teh Taplin Twin).
All run really well, but I can't pick much performcne difference, certainly on the fairly large props I run.
One has an ED throttle, I've found it works best on the greenhead which has the least sub-piston induction.