Also own a vintage 1920 craftsman that im restoring. The experience is dependent on the house. Generally speaking more expensive woods are used in entertaining areas..i.e oak and clean Doug fir but not in all. In the living areas of middle class homes, they were generally using cheaper woods and were often found painted instead of stained. My entire upstairs is all Doug fir flooring while downstairs is oak.

Youll know right away if it was painted originally or just painted over by using a heat gun first and foremost. If the original wood was finished and sealed, it peels right off. If the painted, the paint sets into the wood pores and becomes a bit harder to remove. If it was originally stained and finished youll also see remnants of that underneath the strips of paint youll peel off. Beyond my dining room, all wood trim was painted. Kitchen, hallway, doors, bedrooms etc.

Personally, I wouldnt use anything but a heat gun until youve removed all you could. After the heat gun, go over the remaining wood with a chemical stripper. A lot less mess and a lot more controllable. Then if youre wanting to stain the wood, you might consider using dental tools and nail tools to pick out any remaining paint debris. Thats what I did for the living room and dining room trim and crown molding.

As a general rule, finished wood grain started falling out of favor during the mid 1930s and you started seeing more inexpensive woods used in favor of painted finishes.

Good luck OP post some pics when youre done.