For your home office I proposed an interior with new furniture elements made out of dark wood (the same as the existing furniture), black/ dark brown leather and brass (to match with the chandelier and scounces).
The original carpet was replaced with one in the same tones as the original wall tapistry which you mentioned that will be kept.
The ceiling was replaced in my suggestion with a wooden one, as to complete the traditional image and to give the room a more stylish look.
The TV was placed above the fireplace and sorrounded by a wooden frame to go with the rest of the room. The initail table was replaced with a smaller glass one and I added the bar cart also made out of brass. The area looks more spacoious now due to the glass elements, light structure of the bar cart and the table, but also intimate and inviting due to the leather seating and ottoman.
As for the equipment that you need for the desk area (printer etc.) I placed a wooden piece with brass pulls and dark drawers on the left side of the desk.
Just above the oak part of the walls I suggested placing sources of light to create a more intimate atmosphere in the room.
Also I feel that the existing furniture (desk and book cases) need another new layer of varnish for more color and gloss.
Some elements I used:
I hope you will like it!