The correct bearing tension in your Steering head will dictate how well or badly your machine steers, if in doubt about how worn your top Race is, then at this price, why not put your mind at rest, and fir all new parts? It is just one area of your machine less to worry about.
To ensure you order all the parts you need, maybe new ball bearings, and the lower Race as well, check out the online 'parts list' fiche for your model, and save time and money on shipping costs, by having to order another part later that you overlooked!