Creating a recessed box/shelf within a fireplace

[uluru]

Just removed the 50s monstrosity that was the fireplace in our lounge. It's only a small room and already the warmest in the house so won't be putting any sort of fire or stove in but would like to have a recessed shelf where the fireplace opening would have been. Something like this


Any hints or tips on how best to construct the box within the recess?

[uluru]

We ended up with something much neater than we thought once all the additional bricks built up inside had been removed, so abandoning the box idea. Just need to decide whether to square off the opening or keep the slight curve and whether to keep the bricks on show internally or not.

Edited by uluru on Sunday 22 October 15:53

[uluru]

Photo would be great. Not heard of feature bead before, and even after googling i'm still not 100% sure how it's used.