G`day Cuppa.
As Bidja has suggested above, possibly clutch pedal pivot,dry or slightly dusty and a spray would more than likely cure the problem. One thing wipe off all excess lube, excess is a great magnet for dirt and dust. Pumping the pedal quickly will bleed the vacuum from the small booster and it will not recover as quick as the brake booster, IE hard pedal untill it recovers. Also the feel and noise may come from the thrust bearing or the thrust lever pivot. If the pivot is dry or there has been dust or water ingress the pivot may be noisy, very hard to lube with out removal of bell housing. Thrust bearing, there are two pivot points on the thrust but the wear would be very minimal and again impossible to get to lube.Also the thrust runs back and forth on a shaft this may also be slightly dry and could also create a slight noise . But first thoughts are the pedal pivot.
Stay safe mate, hope its the pedal pivot.