I've got an oak table that was made around 1925, it's stained very dark
and in places where it gets worn, the wood is a more natural oak
colour.

As the table is of sentimental value, I'd like to restore it to
something like it's original look. How do I best do that ?

I'm not sure how the wood was finished after having been stained. The
finish isn't glossy enough to make me think that it's French polished.
What else would have been used in those days.

It was built by an individual craftsman rather than in a factory.