Quick update. I put in a replacement Master/slave kit this morning, a bit fiddly to route through and the pre-kinked pipe didn't seem to be kinked in quite the right places, it went in ok but the routing is not as neat as it should be and a bit loopy-loose in one place. Anyway fitted the kit, lubricated the clutch actuating arm, pressed the clutch pedal a few times, making sure that the slave rod thing was seated in the clutch arm and the plastic tags were broken, so far so good.
Started the engine and pumped the clutch a few times, then tried to put it in gear, no joy, pumped the clutch a bit more and it still wouldn't go into gear. The I noticed that, with the engine running I could put the car in any gear with the car not moving, super strange. Stranger still I found that, with the engine running and in gear if I pressed the clutch pedal all the way down it started to bite and the car moved forward. I couldn't understand what was happening, almost as if I had put the Master/Slave kit in 'backwards' in some way so that that pressing the clutch had the opposite effect. I know it's impossible to put the kit in any other way than it was intended but I was convinced I had done something wrong. However after a couple of minutes of pressing the clutch and questioning my sanity, something 'popped', the pedal started to feel a bit more normal and, thankfully, the clutch started to work correctly. A quick test drive showed all seems to be ok. Quite an odd experience.
Anyway, I am now able to drive the car. Thanks to everyone that chipped-in, appreciate it!