Hi, Maybe I can fill in a little. My Grandmother was Myrtle May Elies, nee Allen. It was only after Myrtle's death that my Mum and her sister discovered, from letters, that their cousin Clem was in fact their half-brother. As Mum told it to me, Myrtle's fiance was killed in WWI, leaving her pregnant. The baby was raised by her older sister.
Sounds like the baby was your Grandfather - my (half-)uncle.
When my Grandmother was left pregnant, according to her letters, she bought the largest gold ring she could afford. A few years ago Mum gave me a beautiful gold ring which had belonged to her Mother, but wasn't her wedding ring. We assume it was this ring. It's one of my most precious possessions.