Hi , what I do in this situation is to take the screws out, get some tooth picks and some superglue .
Remove the machinehead .
Put a small ammount of superglue into the holes , put a piece of toothpick into the holes , and leave to dry .
After about 10 mins , carefully trim the excess toothpick material back level to the face ,
Put machinehead back , re screw the screw back in .
Fixed .
Pete