Do you plan on using it for a heat source, or is it purely aesthetic? If it's a serious heat source, then I'd consider retrofitting an enclosed Jetmaster slow combustion or gas fire. Slow combustion fires are always preferable to open fires like you have- they slow the wood burn and direct the heat into the room, not up the chimney. Check out what the local wood supply and costs are first. If it's aesthetic, may gets run when you entertain. I'd get some black fireplace paint- paint the grate and the inner fire box black. I'd change the hearth- make it bigger, will prevent sparks and scorch marks. Like some others have suggested, keep the slate- change the mantel. Lots of DIY to give a go there!

Hi Jo! Megan from Bluethumb Online Art Gallery here. I agree with scottevie and oklouise that an artwork would be a great option to finish off the fireplace. I love the idea of a concrete render, that will look stunning! I think an abstract piece would look great with the modern lines of the structure, so I've compiled a few suggestions from Bluethumb's artists that I think would look great. Of course, these are just an idea, so let us know if we can help further. My choice would be this intriguing piece by NSW-based artist, Brendan Kelly. I've roughly mocked it up for you, based on a estimate of the actual size of your fireplace. https://bluethumb.com.au/brendan-kelly/Artwork/graze-brendan-kelly Some abstract options that would work wonderfully: https://bluethumb.com.au/dinah-wakefield/Artwork/traces-of-light https://bluethumb.com.au/rachael-higby/Artwork/earth-and-wind https://bluethumb.com.au/susie-monte/Artwork/clementine-abstract-painting-by-susie-monte https://bluethumb.com.au/clairbremner/Artwork/lingering-light-abstract-expressionist-landscape-painting-by-clair-bremner https://bluethumb.com.au/suebannisterartist/Artwork/coral-sky-s-2 Some alternatives to abstracts: https://bluethumb.com.au/johngraham/Artwork/eroded-landscape https://bluethumb.com.au/silvia-rubboli-golf/Artwork/close-encounter-silvia-rubboli-golf https://bluethumb.com.au/elizabeth-wojciak/Artwork/the-blue-bath Once again, let us know if we can help further :)

I definitely recommend having at least one side reserved for firewood - it keeps it all way neater than having a holder or basket for your firewood. Instead of just rectangular cut outs for the firewood, maybe you could have some sort of pattern or shape to the cut out. Like a a curving path of firewood that goes from the floor to the ceiling along the side of the frame unit.

I would attach it to the vanity, it is awkward to try and reach behind you if you attach it to the wall or you could try a freestanding one that you could put anywhere though they might take up a bit of room when space is a bit tight