If it where me i would bleed the clutch,get the c clip and the missing bolt.
To bleed the clutch their is a little bleed screw on the slave cylinder.It will take 2 people one holds down the clutch the other than opens the screw, bleeds the system than closes it.The other than pumps up the clutch(some times you have to pull the clutch back up by hand) than holds again repeat.You want to see no bubbles coming from the bleed screw and have a firm feeling clutch.Some time several pumps are needed to get hydraulic pressure back up.

p.s. only use honda dot3 brake fluid.Also check for leaks.To check the master look under your dash you will see the clutch engagement rod going into the master.If you see fluid build up around that area you master is leaking.Check all your lines for cracks or sharp bends.To check your slave pull back the boot if you see fluid built up you have a bad slave.

If none of this helps you might have a clutch disengagement problem,the clutch is stuck on the main shaft,the clutch pressure plat is malfunctioning,or a spring has poped out of the clutch itself.Or even a bad sincro.Now the million dollor qestion will it shift nice trew all gears engine off ???????????