cheers guys,
4 people pointing at hydraulic side of things does sound promising.
there is new slave fitted, with 2 metal hyd. pipes and 6 inch flex in the middle. the slave wont go back by hand so i removed pipe end into master cylinder and slave returns easily. no fluid is dripping from master cylinder with the pipe not fitted which surely isn't right - therefore am i safe to say and agree that master is either faulty or adjusted incorrectly???

thank you all for your advise, i think if i have to take this bloody gearbox out again i'll go mad!!!!