I can help you with one of Samuel's children. Elizabeth was my great-great-great-grandmother. In 1858, when she was 28, she married William Lapthorn, who was serving in the army (he was a Corporal in the Engineers) and stationed in Hythe at the time, though coincidentally he was also originally from Devon, like his father-in-law. At some point in the next two years, William started serving in Gibraltar, and Elizabeth went with him. Their first four children, Elizabeth, William, Thomas and John, were born there between 1860 and 1867. William was discharged from the army in July 1867, and they returned, briefly, to Hythe. However, by 1870 they were living in Plymouth (William had been born in a small villlage just outside Plymouth, so it is possible he still had family there - I am trying to investigate!); their youngest son, James, was born in Plymouth in 1870. William resumed the occupation that he had started before joining the army at the age of 20, that of stone masonry. At some point in the 1870s, however, the family moved up to Liverpool. I can only surmise that it was for financial reasons; they had no family in Lancashire that I can find, and I believe economic conditions in Devon at that time were not great. In 1880 their daughter Elizabeth married a stonemason, and I think returned to the south west. Her younger siblings also married locally, but remained in Liverpool. William Lapthorn died in 1895 at the age of 69, and Elizabeth died in 1906, at the age of 74, of old age. Three years later, her two eldest sons William and Thomas (my great-great grandfather) sailed from Liverpool to Ellis Island in New York, and disappear from the records. Their families remained in Liverpool.
I hope that fills in one gap, at least! I would be interested in anything else you have found out about the Griffey family; I have mostly concentrated on the Lapthorn line so far!
Tamsin