I made contact with the gentleman who posted the snippet about the de Guehery family 20 years ago.
Ten years ago he wrote a family history called “Some Branches and Twigs of the Elliott Family Tree”, which is on file in the OGS archives in Toronto. His mother, Edna Mae de Geuhery, was the sister of my great-grandmother, Margaret Ogilvie de Guehery. His book has a chapter on the de Guehery family and another chapter on the Cuthbert family (Margaret and Edna Mae's mother was Marion Cuthbert).
He is going to send me the chapters soon.
He also put me in touch with another cousin and this is where it gets even cooler.
His grandfather did a lot of genealogical research in the early 1930s with the genealogy research division at the library in Dresden before that institution was destroyed during WWII. His father continued this research during the 1980's with genealogical researchers in Paris. Apparently, the family tree is complete in detail back to the mid-1700s.
The story includes the de Guehery family's escape from the French Revolution, a beheading, and the loss of a noble title.
I can't wait to get more information.