Original Sosmix can still be bought from AlternativeStores.com
They will ship Sosmix worldwide (hurrah!) and sizes range from 500g up to 10kg!
Delivery is always fast, usually next day, or they have a store near to Newcastle upon Tyne which is open 7 days a week where you can call in and pick up a bag.
Shop now at https://alternativestores.com/