Tried a bit of cellulose paint on the hardboard
it seems to sit ok on it so i'll leave it a while & maybe use that, it's the correct colour that I had mixed to paint the metal part of the dash, theres a litre of it so should be enough, sprayed the inside of the load area
along with some smaller items, used a two pack paint with a non icocyanate hardener, used it before & it gives a good finish but takes ages to dry & tends to run easily