I agree with buzzmummy in that I don't think it would work so well with the picture rail… but would be OK with the coving (if it's fairly plain rather than ornate…?). I prefer the second picture she posted as personally I don't think the modern fire suits the mantel/surround in the first one. Our last house was a 1930s semi and it had coving and dado rail when we moved in. We removed the dado but left the coving. We took out the marble fireplace that was in there and had the square-ish hole in the chimney breast plastered neatly so it was just that - a hole in the wall (with chimney above for Father Christmas!). We put a granite tile in the bottom as a shelf just because we were doing the patio and it happened to fit, and then we had flowers or candles in it. We were getting around to putting a fire in and I was doing research just like you. Never did it before we moved in the end but after my research I was confident it would have looked nice. I do think a squarer shape is more in keeping with the traditional style, rather than the wide sort in the original picture you posted.

The front of your home is lovely. Don't make any drastic changes like painting brick or rendering the entire facade. Instead, look at the front gardens of other homes in your area and study books on domestic landscaping for ideas. The picket fence, although very sweet, is not contemporary. If you want fencing, consider more sophisticated styles. Alternatively, planting a hedge in box or copper beech would give a sharp edge to the property and you can soften the frontage by growing an evergreen climber like clematis or honeysuckle. Additional box balls and pyramids in a partarre bed with herbaceous planting inside gives year round greenery and colour in the summer. Discuss the drive with your neighbour and consider a drive of pavers that will allow water to seep between instead of running off into the road. If your budget extends that far, replace the windows with the original 1930's style https://s-media-cache-ak0.pinimg.com/564x/94/c6/22/94c622f1fca67bef3b6c2a187cd57aca.jpg

Original sash windows are an essential part of our heritage. They’re a distinctive feature of period houses across the UK, from town houses and cottages to stately manors and mansions. As such restoring them is an important part of keeping this heritage alive. That’s where we come in. https://www.bathbespoke.co.uk/2017/04/18/restoring-rotten-window-frame-sashes/ If not maintained properly, timber windows are vulnerable to the effects of rot. This image below is an example window which was sent to us for restoration. The timber suffered extensive rot, with several breakages, flaked paint and cracking. In order to restore the sash; we had to identify all the timber that had rotted, replace and restore the wood, and sand and re-paint the sash with a micro-porous paint that would protect it in the future.

Looks really lovely, I like the way you are able to show the before and afters, especially as the structure is pretty much the same in most rooms. Very calming and serene : )