Such a great story! My family has a similar story about my grandfather, but he completely changed his name.
Way back when, in the early days of public internet, there was woman on AOL on a genealogy page looking for information on her father that matched my grandfather's story. I think she may have been my aunt, but she didn't respond to my message.
Since I have completed my tree with my grandfather's "real" name and family (mostly thanks to a lot of work done by my cousin), I am hoping to find links to others that will prove that Harold and Andrew are indeed the same person. (there are quite a few trees with Andrew's sisters in them and I am hoping for this connection).
It is hard when a person abandons a family and changes his name, "remarries" and has another whole life. (as far as I know, neither the name change nor the marriage were legally done)
This story is very encouraging. I will eventually ask my father to also do the DNA testing and see if any of my cousins have done it as well.
Thank you for sharing!