Thanks Jac
These are a couple of pics of the condition
They have been up in a house loft for years so the main concern was a coating ofgrim that would stop a new coat adhering to the existing, I can only guess that they have cycled from being damp to very warm in the loft space over years that has lead the condition they are in.
I watched a video last night from the early Television museum regarding re-gunning tubes and the guy just used a blade to scrape off the dag and then after plenty of washing when ready masked and applied with a brush, I did not know if room drying or oven drying was used after.
I am getting 4 bottles of this stuff
https://www.betterequipped.co.uk/aquadag-100g-5707
It was cheap enough when compared to the P&P, I could probably dish out to others after.
Adrian