Lots of the plates on these slant-needle machines have this needle strike damage. Having the needle enter the fabric at an angle makes needle deflection more likely when sewing through heavy or dense fabrics. The needle is overloaded and bends upward, putting the tip into the needle plate instead of the hole.
Almost all of my slant-needle machines have damage like this on the all-purpose needle plate and usually, it doesn't cause any trouble. If the damage is catching the thread and breaking it or causing skipped stitches, you'll have to try to get rid of them.
You can grind burrs off of the hole with a fine needle file or Dremel grinder tip or you could use emery cord on a single-needle hole plate.
I just re-read your message and you're saying that the needle is rubbing against this needle strike damage, so I would guess that either something is gunked up enough inside the machine to hold the needle bar too far forward or the needle bar is actually bent. I will try to find some pictures I took to show my daughter where to oil and jiggle her 401 and put them in here.
Oiling points under the face plate
[ATTACH=CONFIG]227031[/ATTACH]
This is a closeup of the lowest oiling point shown in the first picture. Keep this oiled and push the needle bar side to side and back and forth.
[ATTACH=CONFIG]227033[/ATTACH]