Please could someone explain the correct clutch arm adjustment (comes out of slave cylinder). For the fiat X19

I had the engine reconditioned 4000 miles ago and a new clutch at the same time. Everything fine except the garage left off the clutch return spring totally then fitted the wrong one and in the 1300 position. I sorted that out at the time with a new spring and fitted in the 1500 position. More recently I noticed the clutch arm just catching clutch housing when fully extended and there is little movement at the bottom of the clutch pedal before clutch starts to engage. Rather than take it back to the original garage and risk another mistake I want to set this myself, trouble is the supplement in the Haynes manual is not clear to me. So some nice simple instructions would be great.

Thanks, Kevin