restoring old money box,need help?

[smuggles]

hi ive been asked to restore an old money box for a neighbour ,its made from plywood and its not expensive but has sentimental value, on the bass it has writhing in pen, numbers and sums of how much they had inside, but it was never sealed properly b4 and the box is very dirty ,does anyone know a way of cleaning the bass without losing the ink ,i just used wire wool on the rest to clean it up but affraid to try on bass, any help would be great thanks,