Ummmmm, shaking??????? That doesnt sound good, usually shaking like that is gearbox bearings or similar. Well, it could just be that the clutch isnt engaging properly, these cars have auto-adjusters on the clutch pedal, and theyre prone to go, mines gone and the biting point is always moving.

To be honest though if the clutch is original as u say i expect it is that. My 1.6i Orion is on 105000 miles and is on the original, mine however is getting to the point of slipping, where as yours it sounds like the Thrust bearing/diaphram springs are going.

What mileage is yours?

The clutches are peanuts, look on eBay you'll get a 3rd party clutch KIT for about £30, but its the fitting bit, if u can do it yourself your laughing, if not this is where it gets pricey paying some other monkey to fit it......