Hi Richard, many thanks for the suggestion of Steel Seal, I did try it once in my Lanchester, but on stripping the engine last year prior to overhaul last year, I found most of it stuck in the bottom hose !
Probably due to it not having a pressurised system and of course, the Water Pump on these cars are not very efficient.
As for the MG, well it was alll a bit strange, stopped at a friends house and heard a bubbling noise, water being
ejected from the Expansion Tank, and the Bottom Hose felt empty !
Topped up the water, and on my return home the same thing happened, so took it down to a friend of mine who owns a small garage, he recons it is the Head Gasket, strange really , as I had a brand new Cylinder Head fitted only a couple of years ago complete with the new multi layer Head Gasket, even had a new Water Pump and Timimg Belts at the same time.
They are due to pick up my car this morning , to have a look, hopefully, it will be ok on my return from Perth at the end of this month ?
Cheers Al

Ps Should note, that no contamination of either the Cooling System Liquid, or Engine Oil appears to have happened thank goodness!