the rectangular fireback above a basket of graduated rectilinear bars,

This is a cleverly designed wall-mounted fire basket. All cut from one thick steel square plate, the bars have been pushed upwards in turn – the outer until it’s 90degrees, the next slightly less-so until the innermost, smallest rectilinear hoop is still almost vertical. A great design and hard to make.

If mounting as a firepit externally, it would benefit from maintenance as the graphite based finish will in time rust through ( one solution might be to settle for the rust finish, another to paint the metal work with a fire-proof paint).