Don't bother trying to clean up your old screws, just replace with new ones. Easier and prettier to behold!
It will save you time messing around, when you could be doing something more worthwhile, like checking out the product gallery for your model.
You can see other items that you need to order but may have overlooked.
Alternatives screws of this size:
The more comprehensive your order, the better value for you in reduced shipping costs, when divided over the number and value of your order. Please make sure the parts you order are compatible with your model.