Hi Gary,
Was about to turn off my computer when I saw your message. I will be away for a week. Can I suggest that you Join our Facebook group Guernsey Family History. Once joined, make contact with Colin Brehaut in the group. He lives in Guernsey and is related to your line that remained in Guernsey. He would be very interested in what information you have and would be happy to share what he has.
See you in a week,
Diane
https://www.facebook.com/groups/Guernseygenealogy/