Well I came back to trying to free up the clutch release arm today. Bunged some more WD40 on it. Tried levering it again,no luck. Put a big ring spanner over it and pushed and pulled hard - it just wouldn't budge. I was convinced now that it wasn't siezed, it was something inside the bell housing in the wrong place.
Came back in and found this thread...
https://www.landyzone.co.uk/land-rover/leaver-siezed-in-to-clutch.206540/
It made it quite clear that when its siezed - it really can be very solidly siezed. So, back to it, more WD40, ring spanner over the lever. This time though I got some angle iron (a fishing rod holder!) poked it into the other end of the ring spanner and whacked it with a hammer. whacked it loads of times - no luck. More WD40. Then the ultimate in persuasion - the blunt end of and axe. Gave it a good few whacks with that.... and it shifted! As soon as it budged it was loose, literally, it was easy to wiggle it.
Result
The lever still looks as though its quite a way from the slave at rest - further than on the L Series, but the peddle feels right and I got an able assistant to push the peddle while I watched the arm and it appears to move OK - so fingers crossed
I'm hoping this car has been scrapped because the clutch release arm was siezed and the insurance Co. was told it would need a new box - which would need to be imported from the UK.
On a high, I thought I'd have a look at starting it! Thanks for all the advice on what to check before starting it.... but none was acted on
I just made sure I could make a quick escape from either end of the garage, sat in it and turned the key..... It fired almost immediately and sounded pretty good - but there was a screech. I turned it off pretty quick. I'll go back to it tomorrow and see if I can work out where its coming from. It did sound like a belt, but the air filter housing and all the air flow pipework to the plenum chamber was not installed - so it may have even been noise generated there.
So not a bad day - and as a bonus, the Amigos went out as well. The gods were looking down fondly on me today