Is the brown stain or paint? The crown looks like stain but the rest looks like paint.

Its the same dark stain.

poor quality picture . my phone camera is degrading

It is all very high contrast with the chosen white which doesn’t complement the wood. I guess I would pain inside the panels with a more saturated off white or linen color- I WOULD NOT do wallpaper if you are selling.

Sell as it is …

Leave it as is if you’re selling soon.

Agree with the rest, leave it as is, and let the new homeowners decide what to do.

A while back I did a plaster ceiling replacement due to a leak in a dining room, the house was also for sale, and they also had batten wainscotting with a plate rail. They re-stained all the trim and painted walls in 2-tone colors, etc. After the house was sold, I was called back by the new owners to remodel their kitchen, and they already took all that wainscotting off and painted everything one color.