A lot of Shimano cranks from that era had shifting ramps formed by what looks like tears in the chainring.

I'm guessing something else is wrong with it.

Could be bent rings, or improperly setup or damaged front derailleur. I'd check those first.

If you decide crank is toast,
Replacements are available at Niagara Bikes. You'll want something with similar teeth counts to simplify things. The one in the photo loos like it has pretty big rings, 28/38/48 perhaps.

You'll probably want a Shimano A-group Altus/Acera/Alivio. You need to get proper interface, probably square taper. You'll have to check current BB spindle length to see if new crank compatible with existing BB, or just get new BB with crank.