Am I one of the sources, can’t remember if I sent you any scion.
Here are some pictures of my tree.
8/26/2016 Tennosui on right, KG on left
2/19/2017 Tennosui pruned back and leafed out. My Byron Gold plum near the blue bucket is just starting to bloom, it is my earliest plum to bloom. KG bloomed 3/28 in 2016
Here is today’s picture