Charlie, you may have more success by placing this question on the Case Forum.
I've never had a VAC apart and have no manuals for VAC. The design is undoubtedly similar to all other tractors of a similar size.
The pressure plate of a clutch has from 3 or more fingers that, when depressed, release the spring pressure on the clutch plate. To push these fingers, a throw out bearing is pushed up against them and forced forward by a lever attached the the foot clutch pedal. Failure can occur in the fingers (not likely because when these fail there is significant noise when broken fingers crash into the throw out bearing) or in the linkage of the lever of the the clutch. I'd guess that it is the linkage and probably the pivot for the lever that pushes the throw out bearing. These frequently fail because they are not easily lubricated and take a very significant load when in use. Usually, this linkage is not accessible unless you split the tractor at the bell housing.
Since you have a VAC (usually don't have a wide front), you need to brace the engine and front end so that it doesn't tip over when disconnected from the bell housing. Also, you need to support the rear of the engine with a jack. When the engine is secure, place the transmission on a floor jack (on with wheels) and roll the rear end and transmission away from the engine enough so you can get inside the bell housing and find the worn out (or broken) part(s).
I've usually been able to repair these parts by making new ones or welding the old ones. You may be able to find them at a salvage yard or on EBay.
My email is open.