Keep in mind - I agree with Linn that this could be later - but many pieces were reupholstered or made over. I have a sweet art deco era slipper chair that someone reupholstered in the 60s, and I have a fainting couch that someone reupholstered in the 50s/60s as well. The person added a skirt to the 30s chair to match the styles of the times. And it is possible IF this was a 1920s or earlier sofa, it could have been reupholstered and overstuffed to match later sensibilities. The fainting couch/settee is older than the chair, with horse hair, et al. But its REALLY PINK now.
I have seen a version of this done in the 70s in fuzzy burnt orange (ewww. I like orange but it was REALLY BAD) and in the 90s i saw it done up in a gilt look.
I used to sell very high end furniture and was in that business awhile and these are the things I would have advised you to think about.
I think the questions you have to ask yourself are:
1) Are you interested in buying it to resell
2) Are you interested in buying it because you like it
3) Are you interested in buying it because you like it, but want to do your house up in an authentic period.
If you LIKE it, and are drawn to it, and it makes you smile, it doesn't matter how old it is. However, you may be paying a higher price if its from the 20s.
These are the things, no matter how old or new it is that I would look for:
What is the condition of the wood? Does it feel brittle (are their parts splintering off? Broken pieces?)
When you sit on it (not daintly sit but really pop yourself on there), does it creak and crack, or do you hear the frame shift?
Is the upholstery clean to the eye? Or is there a lot of soiling.
Don't be afraid to do the smell test!
If it has a smokey smell, and it is more modern, a good steaming will get it out. But if there is horsehair under there, maybe not.
Are there any springs poking through?
It is hard to tell without a closeup view. Some things are easy and worth fixing, some are not. The frame thing - it might look perfect, but the tell is when you sit and slouch.
If you want to resell it, you have to also consider authenticity, and how much was redone. But if you want it for your house, you can be a bit more lax on that.