Worn centreboard pivot hole

I've lifted the centreboard out of the 'ball and noticed the pivot hole is slightly worn. It has a bit of elongation at approx the 45 degree angle (which I suppose makes sense: the crossover of max leverage on board and least support by the case); placing the end of the bolt into the hole I can swing the bolt back and forth such that the head arcs through about an inch of travel. There isn't really much slack in the hole apart from this, and the hole in the case is nice and tight.

So I'm wondering if I ought to drill and bush the hole - i.e. is it a serious amount of slop - and what would be the best material for bushing? (The board is glass-sheathed wood, btw).