Thanks Steve, I have put some diesel down the bores to soak just so I can get enough compression to fire up (did my usual fill the Land Rover up and sneakily fill a coke bottle with diesel trick). Just turned it over and it's spinning better so I'll let it soak all day, spin it and then do another compression test to see how it is.
But yes, head off is the very last resort, those studs look a bit rusty! I know it won't help but I have been spraying them with some WD40 at every opportunity though!
Bruce, sorry I was absolutely knackered last night when you phoned! Before you started breaking up with me, yes, the tanks out just so I can check the boot floor (which is mint btw!) and check the bottom of the tank and inside, there was a good 5 litres of fuel in it, 20 years old, thats gone in the can for disposal. The bottom of the tank is crusty, but I am hoping that there are no pinholes, shouldn't be. I can pressure test it in the old bath I have using the rad pressure tester before painting the bottom.
Fuel lines need a blow though which I was going to do anyway and I'll replace all of the joining rubbers just to avoid any leaks.
I now have a can of Shells finest VPower waiting to go in. Also some, well I say cheap 20W50 but it's Carlube branded and 5L only costs me £15 at Andrew Page so thats going in for the first start up with a new filter. The plan is to start it up with fresh oil and a filter in, run it up to temp, stop, drain and replace oil and filter. Then I'll replace that oil and filter after about 100 miles or so with some decent Castrol 20W50. As long as the bottom end is fine I should be ok to resume normal service schedules.
Posh camera is out so more photos to follow!