They look a lot like ours did when we sanded them back 10 years ago. We used a semi gloss coat (not sure of brand, but think ours was clear colour). The photo makes them more orange than they really are.They are very easy to maintain (vacuum once per week and light mop every so often). We have them throughout our house and love them.

We did pressed metal splashbacks on a display in a kitchen showroom I used to manage, and as such many of our clients opted for the same look. Powder Coated is definitely the way to go. It stands up really well for durability and is in fact relatively easy to clean compared to many splashbacks. Often people think that glass or stainless steel are the easiest for cleaning, but due to being such a flat reflective surface they show up every splash and if you're going to clean them you really have to clean the full length of splashback. The textured surface of the pressed metal means that it doesn't reflect the same amount of light so you are able to get away with cleaning it less often, and you can also get away with just cleaning the dirty area rather than the full length. The biggest difficulty we found was getting the splashbacks installed as there aren't really any tradesmen who specialize in fitting pressed metal, and those that were willing to cut & fit it were concerned about what would happen if they damaged the paintwork. We had the panels cut to size first before they were powder coated to minimize the risk of chipping the surface.

strip part of the brick and mantle back to orignial if the exposed colour lines up with the room, strip the whole thing. Looks so well crafted not to pay respect to the past

The stained glass windows seem to be at odds with the exposed brick, but probably match the original part of the house. If the stained glass windows are giving privacy from an overlooking neighbour I would keep them, and work to make the brickwork more like the original part of the house, so it seems less incongruous. This could be done using a traditional wet plaster or solid plaster technique, which you would need to complete befor your gas insert fireplace is positioned. I would finish it of with a traditional timber fireplace surround and mantle piece, which would be the focal point of a more contemporary room, but link in with the original architecture. Best of luck, Dr Retro of Dr Retro House Calls