. A big thank you to everyone out there. Your collective wisdom has been fantastic. 
A quick summary:-
By a cheap van.
Has very bad oil leak.
Decide to take the engine out and go for a rebuild.
Engine had been rebuild before, one head is a replacement , neither look to bad, however signs of leaking head gaskets on 2 of the 4. The bores and pistons are not bad, but piston rings have lost their spring. Looks like the bores have been deglazed but are not oversize.
Clutch plate down to the rivets
Oil cooler is the source of the leek, the cooler not the connection between cooler and block.
Split the crank case.
Camshaft a right off as are the non hydraulic tappets that had been installed (
read up on running in new cam)Main bearings in surprisingly good condition and not oversize.
Shopping list. Time for a game of the price is right
Gasket set, oil cooler, piston rings, big end and cam bearing shells. New camshaft (hydraulic profile), new hydraulic tappets and matching pushrods (thank you California), clutch.
Then spend 2 weekends on the tinwork, clean, patch holes, paint.
Now it’s time to follow the “how to” guide that is “Oops”
Back in the van (no nice test beds for me) and compression test:- all reading between 105 and 110 psi and the oil light goes out while cranking. Happy me.
But it won’t start...
has to be timing. Read and reread everything I can find.. go on holiday to visit family . Come home.. now I can see what is up . My dizzy has several marks around the rim and I have chose the wrong one so timing was 40 ish degrees out. This morning woke the neighbours by running in my new cam
Time to celebrate... I was going to go for a run tomorrow but don’t think my head will be up to it.
Next.. get back in touch with campershack about sorting out my LPG. It was disconnected when a new exhaust was fitted and the “probe” was not replaced. Campershack are talking about using heat from the oil for the vaporiser (apparently marine engine do this)
Then there’s just the rust, dents, paintwork and interior....Oh and apparently it’s time we thought about moving house
reset the tappets.. tighten and torque all the case bolts.. drain the oil.. fit new filter..