Small flat in Hampton Hill. Cleaning, regrouting, painting and adding some shabby chic mirror and small details. Budget about £60

Such a great question, I hope you get some responses as I'm sure the floor will look great when restored. I'm no expert on conservation but we have just restored our porch tiles. They are encaustic tiles, some were chipped and we replaced these with extras we had from another room. We have also installed an encaustic tile from fired earth in our cloakroom. Fired earth do a range of cleaning products for tiles. I've no idea whether these are the best on the market but my tiles certainly came up a treat. Just google fired earth tile restorer and you will see the different products. Marble staining might be tricky to remove but I would definitely give it a go. Alternatively you could pay someone £££'s to do the work!good luck with your project, it sounds very exciting.

Thanks @whirligig, we used some pre-mixed grout and went over it all with a float, cleaning up the excess afterwards. Then once it had all dried, went round and scraped off any flecks etc. and polished it up. Good tip with the cling film @maplecottage! We haven't made anything too messy yet, so we'll see how we go. Might get some sealer spray as it looks fairly easy to apply.

If you can't source them consider reusing the tiles behind the sink and in their place get a larger mirror