That sinking feeling

[JanDebL at aol.com]

While my wife' 87 5KTQ was parked for the summer (she's a school teacher) the 
clutch pedal dropped to the floor.  I tried driving it for several days with 
mixed results.  About every 20th use of the clutch, the pedal would stay down 
but could be pulled up with my toe any it worked normally again.  Next, I 
flushed & bled the system but this had little effect.  This morning, on her 
2nd day back to school, the pedal went to the floor and stayed there.  
Obviously its either the master cylinder or the slave cylinder.
Any BTDT's?             
Any betting people out there?
Also, any suggestions on parts availability, pricing etc?

TTIA, Jan Lahtonen