[Blindstitch]

If you don't want to go with a scout scope combo you can have it drilled and tapped but I have a feeling if you go that route eventually it will cost more than buying a budget Savage Axis or Ruger American type rifle in a more common deer caliber.

I'd keep grandma's rifle the way it is. Modified it's only valued to yourself. Feel free to teach the kid how to use iron sights though. Most of us started with iron sights.