@tentative3 the fire isn’t one of the cassettes, it’s called a Spartherm Premium V-2L-80h. Photo attached of the whole unit before it was boxed in.
I looked for ages to find somewhere that sold recessed bookshelves that we liked. In the end, the bookshelves were designed by us and the drawings were sent to a carpenter 100s of miles away to be built (felt a little bit risky!) they arrived on site and were perfect! The panels under the shelves are to hide and provide access to all the bits and bobs for the underfloor heating.
On a night, we usually have all the lights off except the light boxes and the lamp on the bookshelves (also Philips Hue bulb and connected to the light boxes). It just gives the room a lovely warm orange glow.