The fingers on the pressure plate are uneven causing the peddle to pulse. UPneven fingers are caused by uneven diaphragm spring pressure. ( or uneven coil spring pressure on a lever clutch ) No real fix, just drive it and pay attention to slippage.

Be sure that if the clutch starts to slip at some point,replace the clutch very soon.
A weakening / cracked diaphragm spring will loose drive rapidly. ( A thin clutch disc will slip also and is the most common reason for slippage. )