He's made a 'brick lining', which I'll have to paint up to look like bricks. The mantle and lower woodwork will likely be stained and varnished, while the upper wall will get painted.
As far as a 'fire' goes, my idea is to find some similar-looking (but much larger) logs and burn them outside in our brick barbecue, take lots of photos as they are burning, so I can Photoshop the flames into this fireplace if I need to. I should have thought of that last week when the chestnut tree was thinned and all the branches (big & small) were cut up and put out for 'Garden waste'. Then they'd certainly have looked the same. But it's too late. They are all gone. People driving by took it all for their own firewood. So I'll see. Maybe the dolls won't actually need a 'fire'.