I can heartily recommend Chris Bowers' interesting nurseries. They are able to source some of the old English varieties that I am collecting for my 'Ancient orchard' here in the New Forest. I could only find these with them last year. Don't forget everyone, as May and June bring droughts you will need buckets full of water for each plant to preserve the young root development. Just because everything else is demanding you attention just then, these precious individuals cannot manage until they have formed a proper new rootball this may take several years , depending on soil and weather. I used micorrhiza root grow and a handful of dried seaweed in their planting. This last is both water retentive and nutritious. I always return to Chris Bowers for reliable trees.