Terry,
It's not a big job to pull down the clutch.
Why don't you do it then measure the plates and springs to see if they are in spec. (don't have the figures with me cause I am at work) You will find the tolerances in the workshop manual.
Also check the plates are not warped, (this can be done on a sheet of glass, it's the nearest thing to flat that you will find).
Another thing to check is your cable, make sure it has'nt got a snag in it.
We had the same problem as you and bought a new set of springs and plates, only to find out the cable was fcuked.
Bought a new cable and now have the sweetest clutch you could imadgine, pull it in with little finger.
Hope this is of some help.
Regards Sam.