Ornamental cherry tree (Allerton L19)

Young ornamental cherry tree, about 1.5 metres tall - deciduous with pink blossom in the spring. I got sent this instead of an edible cherry variety about 3-4 years ago, so I'm afraid I don't know the cultivar nor its likely final dimensions. I dug it up today trying to retain as much of the rootball as I could and have put it in a bin bag with some water, so hopefully it will survive a day or two before planting.

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