This isn't the right location for a display cabinet that aligns with your wainscoting. Select a long sideboard, even one with glass doors to display your collection.

a long enclosed piece of furniture..

Don't buy framed art just for the sake of filling the wall, hang something that means everything to you.

store collectible IN an enclosed cabinet. Highlight something special, change it out rather than showing everything.

when everything is special, nothing is special.

Thank you! I do have an antique long cherry buffet that would be enclosed that could fit here nicely.

Lets see that then . Really no context no help but that cabinet has to go. We need to see the whole room to even begin to help

I vote for plates.

I think the cabinet would work because it's aligned with the wood trim.

Try this:

Remove the stuff from on top of the cab to see the trim and make a clean line on the wall.

Then give the eye the impression of a tall unit by hanging plates on the wall only above the cabinet and almost to the ceiling.

For your Cherry buffet, a horizonal display for your plates.

I like the long sideboard suggestion.

The wall area above the tall wainscot is not too tall. Have you considered painting that wall the same color as the wainscot?

Wallpaper could work well, but only choose once the furniture is decided on and be sure it works with your rug. If you paint the choice, the entire wall will feel coordinated and quite impactful. (Maybe edit contents and the surface if using your present piece).