Are you looking for cosmetic advice or a complete redo?

I would paint the cabinetry a shade or two darker than the stone of the fireplace and update the hardware. I would also remove the mantel since it doesn't make sense to have it and the keystone. I would paint the brass metal black with a heat proof paint and look for a pretty firescreen to put in front.

Probably cosmetic at this point but open to all suggestions!

I agree, if you painted out the built-ins either in white or darker than the stone and even just painted the brass black to match the screens it would look significantly better.

ditto what katinparadise advised.

If you don't have a lot of things to put on the shelves you might want to remove the cabinets. They detract from the fireplace which is very pretty. I'd remove the mantle.

* I'm not suggesting that wall color*