I'd call something of that era, with those mouldings, a Craftsman! Enjoy!

Chelsea, it’s a lovely space, congratulations! Love that your asymmetric mirror and colorful dining set. I’m no expert, but yes the exterior has elements of Greek Revival. Original hardware and lights may hold clues — post pics of one of your doorknob back plates, hinges and any original lights in the hallway or lobby, if you want folks to help you sleuth. The DR built-in — how about taking out the shelves, installing a light and hanging a great artwork there? Or, a small decorative shelf holding a sculpture or stunning vase? Maybe even use an architectural fragment for a shelf? Either way, wallpaper the back to add color and drama.

The built in looks deep, so another possibility is to install glass shelves and set it up as a bar.

Ps, look closely at your walls — there were almost certainly several wall sconces, and often the electric connections are still there and viable behind patches.

Wowww thank you I love your ideas for the built in! Especially adding a light, some wallpaper, and a nice piece of art. Where do you think the sconces may have been? Would love to add some.

In the LR: two above the mantel, and near doors — esp. the entry to the DR

These are actually the real-estate photos (haven't moved yet), but found these images of door handles (apologies, they're pixilated).

Bingo, those are a match for Greek revival!

Your niche is an unusual shape, I feel it has a story to tell. What’s on the other side of the wall?

Thank youuuu! Yeah it’s odd eh? Would love to make it curved. The main bedroom is on the other side.

It's a very "modern", Deco-infused version of the Greek Revival elements. Those elements are there, but stripped down: the coved cornice could be in any 1920's-30s interior. The parlor floor cornices in the 1830s Greek Revival house I lived in where deeply coved but then overlaid with brackets and acanthus scrolls and such. (And then parts of the house were still Federal, more or less). Almost nothing is completely pure, or designed in a vacuum, so whever the underlying style or period is, will often be mixed with whatever else is going on at the same time. Particularly when its a Revival-Revival, like this is, later than the original Greek Revival.

The niche is in a very prominent spot, yet its trim is much plainer than the rest of the house. And it looks like there’s moulding under the interior angled areas, but not elsewhere. Did it have doors once? Or was it a religious shrine possibly? You’ll have fun meeting your new neighbors and finding out what they know about your building!

Examples of architectural salvage shelves, might be fun to mix styles, add texture

So refreshing to see a stewardship approach to renovations here instead of the "tear-it-out-and-surburbanize" mentality.

Not sure what your priorities will be, but you’d get a lot of impact replacing the DR and kitchen ceiling lights, and reinstating the missing LR ceiling light. Personally I love antique lighting from the 20s, but there are many affordable modern lights in the same classical styles.