Kristin, I would love to compare notes with you. I am aware of the 4 children they had together but I am sure you could add to what I know.
I don't have a picture of Arch, but have pictures of two of his sons.
I ignored this family for too many years thinking that the family info passed down to me was correct.After 20 years, I started to collect support documents and discovered that the info was wrong.
Since that discovery, I have spent a lot of time trying to sort it all out, but it is not easy. I have posted many places hoping to connect with the family of Dr Marcus Allen.I can follow him on census records and I know that he and his wife both died in California, but I haven't found anyone else working on that line.