Firstly, two of the Grants, running gear off, tracks off, de-hatched, old sandshields (made out of the bubble plastic that used to contain series 1 Airfix kits in the early 1970s, and a very poor substitute for plasticard - ersatz at its worse) binned.
Sanded down to reduce the rather prominent rivets and smooth out the odd globit of tube cement (all I had then. All there was, I think), running gear superglued back on.
First coat of Humbrol 93 on the hulls and running gear, and Humbrol 119 (rust) on the very shiny tracks. Interestingly, the vinyl tracks are in very good condition after nearly 40 years, and I suspect that is partially due to the thick coat of gloss silver (Humbrol 11?) with a touch of white. The Matilda is also Airfix with a Britannia commander, and the Dingo (a favourite vehicle) is Minimi Miniatures. Next stage, new sandshields.