It's easy to know if you have a Verto or the original type. The Verto slave has a tab in the casting for a return spring, and uses a "Banjo" style hose to the cylinder body. This original style unit mounts at the top of the flywheel housing, and acts on the longer (6-8 inches) throw out arm.
This slave cylinder was also used on the early Sprites and Midgets that used the 7/8" bore cylinder (original factory number GSY110).

The same slave cylinder was used in Sprites & Midgets that used combined brake & master cylinders, 948-1098cc from 1958-1966.