Thanks Ted,
I already have and its fine it just needed a fair bit of mixing with a plaster/paint mixer in a drill and it was ok.
I think the main problem with old paint is evaporation due to leaky tins and also the pigment settles and is very difficult to re-suspend unless you use something like a mixing attachment
Funny thing is the chap who sold it to me was a scrap man and he lived on site in a bungalow with some other outbuildings dotted around.He had huge supplies of this stuff and had painted the bungalow all his outbuildings ,fences and car crusher and site vehicles with the stuff over the years so the whole place seemed like a desert scene!!!
Thanks for the tip off though.
Once I have painted it Ill post some images of my oxidation chariot in its new paint:D