Not much help here, but . . .
Had one defect in the cockpit of my 97 H340 and that was a small air bubble that was on the inside curve on the cockpit seat. That was easy to fix. I've seen some very neat repairs on the nonskid. The ridge and valleys were matched with a very careful use of a fine file and very fine sand paper. I've also seen a bad factory repair on a Hunter. My talented friend felt that even that could be repaired with a little handy work. Unfortunately the area was just stamped with the pattern and thus did not match the rest of the pattern. Suspect this is what you have.If you're really intent, get the matching gel from your dealer or hunter, fill it in and try the the "filing" techneque. You might try your hand on a piece of wood first before you work on the boat. I don't pretend to be an expert in this area though I've done some gel repairs in the past.Or if you have a really good repair person in the area, they can do it for you. Check a sample of their work though before you let them start.