The trim on top of the black should be black as well.

How old is the house? How many owners has it served? If it is really old, that might not be the original color. I have an old house and our goal was to make the original owner proud. But we also remind ourselves we don’t live in a museum, this is our home. So, we do have indoor plumbing, AC, electricity, a gas range. Maybe once your furniture is in the spaces, you might want to paint the window trims, but maybe not. The house is not in a rush so you needn’t be either. Relax, research.

I think the wainscot is too low. I know they did it this way to go under the window sills, but it feels out of proportion to me. Here are other views of wainscot paneling; you can see how the height of it makes the room feel more balanced and it goes around the window, not below it:

Winter Pond- Dining Room · More Info

Dining Room -Custom House, · More Info

Not really wild about the black wainscot and mantle, unless you decide to do a very hi-gloss treatment.

It's 188 years old and mostly original. I'm just curious why someone would paint the wainscoting two different ways in the same house, it's no big deal though.

My house is almost 200 years old with all original woodwork and the wainscot runs under the windows just like above. The top rail blends into the window sill.

I like the way the height of the wainscot matches the lowest panel of the door.

As far as the difference in finish, a couple things come to mind. First, previous caretakers of the home may have just done whatever struck their mind at certain points; it's different now that you are looking at it as a historical restoration in 'one piece'. I even see this in my own renovation - there's places I used satin finish in one space and it butts into a gloss finish in another (oops!)

The other thing I notice in those rooms is that the room behind it has what looks like shiplap or some other horizontal wall - it's possible that is a less formal part of the house, or not meant to be seen when entertaining. And that can lead to different choices in finish as well. Kind of like how some houses have formal stained wood in the living/dining, and paint-grade pine in the kitchen.

My chair rail runs at the same level as the window sills from 1803. The higher wainscoting seems more recent style. Mine is embedded in the plaster so I know it is the original. Don’t you love the quirks of old houses!!! If you are sure the two are original, it could have just been a difference in the proposed use of the room-one more formal and public than the other. Although I have nine foot ceilings, several of the doorways are 72” inside height!

Interesting remodeling, my ceilings at 11' and 12' but the doors are all the same height.