Other Clutch master cylinder problems?

I am struggling to get my head around the clutch master cylinder any help would be much appreciated.
If I disconnect the pipe that comes directly from the master cylinder I don't get any fluid out even if I pump the pedal and the reservoir is full?
I removed the master cylinder completely and stripped it down to try to understand the problem and I am now even more confused as there is one piston with two rubber cups about and inch and quarter apart and the hole in the cylinder falls between the two cups so the fluid falls between these two cups from the reservoir so how does it get pushed out? is it forced passed the first one? how does it work?
Help please as I'm going round in circles now

Model and year?

Classic two door, 1972 but its just a standard old classic clutch master found on loads of cars (if that helps)

This is a link to the new version


http://www.paddockspares.com/aeu1714g-clutch-master-cylinder-lockheed.html

Think I'm going to stop messing around and just buy a new one it's not worth the hassle.