i think i might have spotted a problem
have you taken the chrome clutch cable arm out of the clutch cover and refitted it?
the little retaining pin is missing in your pic.
if it fell in behind the gold brackets it may be keeping the pivot arm from moving in enough when you pull on the clutch.
did you check that the pusher slides in and out of the clutch cover when you lift the clutch cable arm ?
it should lift about 4mm - 5mm away from the cover
the clutches are pretty simple to reassemble, and check
also when fitting the clutch plates onto the centre splines of the hub, did they slide on nicely?
they would have worn to suit the hub, so they will only move on the splines when they are lined up to the correct previous place
otherwise it can cause the plates to bind up on the splines
just keep turning the plates one spline at a time, to find the nicest/smoothest fit
if you have to force it a little to get it on the hub, it will bind and become sticky.
i have just taken a step by step shot of how to reassemble it
compare it to your clutch
clutch outer
springs fitted
pressure plate fitted, make sure to align the spring seats on the other side with the springs in the cover
clutch hub fitted over the pressure plate
clutch plate
steel plate
clutch plate
steel plate, circlip wear mark to the outside
compress hub into the clutch housing
fit circlip, then turn the clutch over.
at this point you should be able to push on the outer bearing side and feel the spring compress a little as you apply force, this also shows you that the clutch plates are not binding up inside.
now to refit the springs refit the damper springs,
now it is ready to refit to the crankshaft.
make sure the tension washer is facing the correct way, the stamped outside marking to the outside
and then refit and do up the nut firm.