I asked Chat GPT to estimate the age of the hearth and surround, and this is what it came up with. Obviously this might be incorrect but it does suggest the fireplace might be original to your house if it's c1910....
"Focusing just on the hearth and tile surround, and ignoring the gas fire insert itself, the features suggest something older:
The glazed tiles in cream and greenish tones with moulded floral panels at the top corners are characteristic of Edwardian and late Victorian fireplace designs — roughly 1890s to 1910s.
The shaped arch and relief patterning were typical of tiled fireplaces fitted in middle-class homes of that era, often paired with cast-iron inserts for coal fires.
The tile colours (olive, beige, cream) became especially fashionable in the early 20th century, moving away from the darker tones of the high Victorian period.
So, the hearth and surround likely date from circa 1900–1920, Edwardian or just post-Edwardian in style — later fitted with the gas fire you see now, probably in the 1950s or 60s when many such fireplaces were converted."