X-Minus-1
An incognito original design by Steve Okeefe
This one is a bit of a wolf in sheep's clothing. Look carefully and you will see that the drop arm is not a drop arm at all, and that this chassis is in fact a long wheelbase, short guide lead Iso-fulcrum with the hinge located at the front of the motor bracket.
The front wheels are 3/4", the rears 7/8", but the odd shape of the X-Minus-1 body calls for a 4-3/8" wheelbase, and even with a shortened pickup guide, allows for only a rather short 4-3/4" guide lead.
In this photo set the Iso-fulcrum down stop had not yet been installed.