Thanks for helpful answers so far-
I'll definitely try finding loads that work first. And I'll start load tests with the Marble's peep sight to eliminate scope & mount issues.
Unfortunately I don't have much of the rifle's history. Grandpa and Grandma are gone and my folks left town when Dad went to flight training and have never lived in the old town since. Only story I know about the rifle is that I got to shoot it exactly once as a kid when we visited for Christmas. (Could barely hold the muzzle up to shoot that darn stump!)
I have no children to pass it to as a family heirloom. My sister's family are anti-gun and she has daughters. So there's no real passdown value.
I'm just hoping to be able to make it shoot well which is value for its own sake. But I'd like to have a Plan B. Rebarrel would be nice if it comes to that.