Hi. I've reproduced your room in a 3D build to help you visualize in a better way. To maintain a foot flow I have centered the sofa facing each other. You can add one or more swivel chairs which you can tuck away or corner them when not in use. Mounted tv on a wooden panel opposite the fireplace. This way it serves as a family room as well as an entertainment room. Perfect for a winter evening when it's too chilly to leave the fireplace but also wouldn't miss your favorite show. If you can get rid of the piano, you can place two chairs and a bookshelf and create a little reading space. Let me know if you would want me to work on more layouts. Always happy to help!

Actually it was original. The gentleman who’s dad built the house when he was a little boy use to come each summer to have lunch with us. He told stories of how he and his siblings would peek into the bathroom to spy on their parents. He was in his late 80’s when my husband and I met him so we weren’t positive if his glass block memory was correct until we unearthed them yesterday. We are very fortunate to have met him. He provided us with 1938 construction pictures. Truly a gift.

I need a pic of that whole space IMO no chairs since they would block the doorway what is it you think you need other than a nice shallow shelf with a lamp maybe and the wall painted an accent maybe .

https://www.ana-white.com/woodworking-projects/modern-farmhouse-diy-staircase-railing I think to use this concept you need to beef up the wood members. Using 2 x 4s is no better than a temporary construction railing IMO.