By viable I mean workable, functional. A chimney sweep or a builder adept in chimneys will give you a report. Certainly enquire about a future gas fitting rather than logs if possible. I say this as a fireplace anywhere is delightful and, if downstairs, it could heat upstairs through the house, to a certain point too. If you look at the quality of the brick laying, you will see that its not meant to be a feature which is why it was rendered, but that is choice only. Certainly seal the bricks. Good luck and stay with it if you can. Everybody loves the romance of a fire.

Depends on what you are planning to do with the room whether to paint or not, both mantels are missing their inserts. The first photo does look like it's two pieces, the top is Art Nouvea , the second timber mantel looks Art Decco. For me the first photo with fire place I would look into a gas insert to fit, not sure whats on offer, but similar size as how to girl, you can get plain metal fireplace inserts with out tiles. You could use either mantels but I think I'd find another use for the separate mirror, perhaps over a side board cheers

I take it this room is the living room, and that you definitely want to have a fireplace for ambience? I would first consider which would be more useful, a fireplace or some bespoke joinery such as the floating entertainment unit. Also, how long do you plan to live in this house and do you need to think about future resell? What do buyers want/need more, ambience or storage? I’m all for having what suits you and your family best. If you decide to keep fireplace, I would build out the wall in order to accomodate a gas fireplace with a more substantial surround to suit the style/period of your house. You would lose a section of that wonderful Axminster carpet, alas. Love it...we had very similar one in a previous home. If the room is large enough, perhaps you could also have a floating unit built at the same time, if budget can stretch. I am curious about the carpet...is it only in this room or throughout much of the house?

A lot depends on the size of your TV and the size of your fireplace insert. If you have a clever cabinet designer than an adjacent arrangement always looks good, but you have to know what you are working with. Check out Sculpt fireplaces for some freat in-built options. https://sculptfireplaces.com.au/collection-category/contemporary-inbuilt-fireplaces/ Best of luck with your research, Dr Retro of Dr Retro House Calls