Pleased to say I have got the old girl going! I found out that it had actually been stagnant for 3+ years!! Proves how tough these engines really are!
So thought I'd follow up with what I did to get the engine going for anyone trying to do the same:
I first managed to turn the engine using a crowbar jammed into the front of where the crankshaft pulley nut is to see if it was seized. Stiff. I followed fenby's advice by checking the wires and straps. The solenoid was ok. Believe it or not the engine wanted to turn at this point but was very weak. I tired jump staring it, but whilst it turned with a bit more enthusiasm, nothing.
I took out the spark plugs and I was advised to put a few drops of engine oil down there which I did. The plugs had heavy black carbon deposits (which I think means rich fuel mixture??). I span the engine without the plugs in before replacing them with new ones.
From this stage I wasn't getting much further but seemed very close to starting when it was connected to the range rover. I checked the earth strap from the negativer terminal to the chasis which was ok. I couldn't actually find another earth strap from the engine or associated components onto the chassis at this point and even had the starter motor off to re-test it (I assumed ((dont know why!!)) that this was earthed through its body by being bolted on).
I checked the fuel pump was working, changed the fuel pipe and put fresh fuel in (I can't seem to find four star anywhere? does anyone do it now? I just used unleaded and put additive).
I had help from a more mechanical minded neighbour from now. We checked and cleaned the points in the distributor and re-did the gap.
Tested seperatly we checked the battery as the engine just had no life in it when not jumped by another vehicle. It was ok, and at this point my neighbour pointed out that hidden behind view of the wing bolted onto the chasis was a broken off earth cable! No wonder it wasn't turning. A walk down to the motor spares shop soon had us with a new earth strap bolted onto the starter motor to the chasis. Again we tried and she roared into life, choking hafl the town with smoke.......and then she cut out.
There was a slight fault with the choke cable whereby it wasnt opening and closing the butterfly valve at the top of the carb, choking the engine with no air. A little more tinkering with the spring that holds it onto the movement of the cable and away she went again, purring away beautifully like she had done previously.
Now its a full service and a clean up and an attempt at the MOT!
(woah, apologees for the essay but just had to share my success!! and it may be usefull to someone like me!)