Thank you but no - I did find a couple of polished brass ones - I did think I could try to matt/blacken it myself as a last resort?

Hi. It’s called Lotus wallpaper by Galbraith & Paul. Here’s the Houzz tour: https://www.houzz.co.uk/magazine/my-room-an-extension-gives-a-period-home-a-relaxed-family-space-stsetivw-vs~118161334

Possibly an old elica model with a name like cappa cucina, did find this though https://appliance-source.co.uk/luna-island-180-cooker-hood?utm_source=google&utm_medium=shopping&utm_campaign=google_shopping&gclid=CjwKCAjwgdX4BRB_EiwAg8O8HVguPpji_xAzigR_RdZCpsOYmbQWyNPe-p-z6EkjjUTHYOTQaWOhThoCrzsQAvD_BwE which might be of interest

I assume you’ve tried B&Q? They do sell just doors if it’s still in manufacture. Otherwise there are plenty of door suppliers online and you just have to find the nearest match. You can get paint colour matched at B&Q if colour is not quite right. Found this one in their clearance sale which probably means stocks are very low.