Slate slabs (OK if broken) (Llanbister)

I'm still looking for additional pieces of slate to 'crazy pave' remaining area of a hearth but must be 30mm thick and ideally fairly smooth finish to match pieces already kindly gifted. I need between 1.3 - 1.5 sq metres to complete. Please let me know soon if you can help as the wood stove is due to be re-fitted soon. Thanks.