Where to buy Derby Epsom leather by Tanneries Haas?

I am really curious to know where people buy Epsom leather from Tanneries Haas. I see a lot of people working with the leather, but only found one retailer in the US which does not have a lot of colors available and sometimes only sells half of the hide or even smaller pieces. Does anyone know where you can buy this specific Epsom leather? Preferably in Europe

Thanks