Update. I am 95% positive the high revs are due to the "Carb Adaptor Assembly" O ring not seating correctly. It seems as if the carbs are a loose fit to the inlet manifold and held in place by the large spring and bracket that runs between both carbs, the 4 studs on each carb attach them to the adaptor plate not the manifold. There is quite a bit of movement at the point where the assembly meets the inlet manifold. I started the engine, revs running high I lifted the carbs and the revs dropped, then let go and revs rose again so lifted and wiggled up and down and the revs dropped and stayed down. I now have it running of sorts but will be looking for a supplier of this O ring. Have checked Wadhams but they don't have them listed. Anyone know where to get these before I do a internet search. I don't know where to start with this one as it's not a carburettor part, more of a Rover adaption.
Regards