You said here that (as I read it), James Henry Blagrave was your great-great grandfather. Well, I believe that, this same James Henry Blagrave was my great-great grandfather, as well.
My reasoning is this-
Last week I was discussing my family tree with my brother John Christopher Blagrave (now lives in Spencer, IN), and he had a James H Blagrave born in 1825; as a note for our g-g-grandfather and the father to my great grandfather James Henry Blagrave, born in 1860.
James Henry (my great grandfather) married Marie Annie Harrison. Further, I suspect, because my grandfather once said we were kin to the Curry's, that James Blagrave who was born in 1793 and married Peggy Curry (see Michelle Taunton website for Henry Blagrave I descendants) was probably (as well) a James "Henry", and the father to the James Henry born in 1825 and married to Betheat, as you had mentioned. So, I believe we do in fact share the same great-great grandfather. At least it is very likely.
You see, I am on of the Madisonville, Texas area Blagraves. I am James Elbert Blagrave II, the grandson (and as fate would have it as well), the adopted son of my paternal grandfather Elbert Blagrave; who was the son of Marie Annie Harrison and James Henry Blagrave, both buried in Hopewell Cemetery in Leon County, Texas (outside of Madisonville and close to Normangee).
Your Grandfather Leonard Blagrave was, I believe, a first or perhaps even a double-first cousin to my grandfather Elbert Blagrave. One of my grandfather's first cousins was actually a double-first cousin. I do not know which. Was your great-grandmother's maiden-named Harrison? If so then Leonard Blagrave was that double-first cousin of whom I speak.
Of course, if your great grandmother was not a Harrison, I still believe (at the least), that my grandfather and yours were first cousins; making Willie Willis the brother to my great grandfather James Henry Blagrave, born in 1860.
Do you have any record of your great-great uncles (that would be your great grandfather's brothers). If what I suspect is true, and if you do have records of your great-great uncles, there would likely be a James Henry Blagrave in some of your records.
I vaguely recall meeting a man named Leonard Blagrave, when I was very young (in the mid to late 60's). This Leonard Blagrave was my grandfather's cousin. He was visiting us at my grandfather's farm, in Normangee, Texas; just after my natural grandfather (Elbert Blagrave), and grandmother (Veta Fulbright-Blagrave), adopted my brothers and sisters and me- from St Mary's Catholic Orphan's Home in Galveston Texas. My dad (James Elbert Blagrave) was still alive at that time, but circumstances led my grandfather to demand the rights from the state to legally adopt my siblings and me.
Anyway, I do not mean to ramble, but the details to how I became my father's adopted brother are none-the-less true and a bit different.
Please feel free to contact me, with anything you may have to add to this information. I believe that I am so very close to the correct lineage route, and have nearly made the connection all of the way back to Henry Blagrave I.Feel free to send this information to whomever, you believe has valid information to add. I will also post this on the genealogy.com website.
Some more conjecture -
If James (Henry??) born 1793, who married Peggy Curry were the parents to James (born 1825), then the group that came to Harris County Texas(Cedar Bayou) were in fact (at least)two brothers and a sister. The group being consisted of at least, James (or if James was dead, his children and perhaps his wife), his sister(Jane (Jincy)Blagrave), his brother, Emmett (the father to Isaac Newton Blagrave) who died at 29 yrs. Isaac Newton Blagrave's wife re-married a man in Texas named Clay. Clay's daughter Fannie is very likely the same Fannie C that married Hiram Baker Blagrave recorded on the tombstone in High Prairie Cemetery outside of Madisonville, Texas. Hiram Baker Blagrave is Isaac Newton Blagrave's son. So Emmett, James and Jane (Jincy) Blagrave would be two of the brothers and one sister of the six children, whom were the children of Harrison Blagrave and Esther Harbeson. This makes sense, as these were all Blagraves originating from KY thru IN and came to Texas around the Texas Civil War period.
I called Beth Blagrave, the wife to R. Ashley Blagrave (I believe the R. is for Reuben), in Iola Texas. Ashley is the son of Reuben and the great-grandson to Hiram Blagrave. I believe that she said that Hiram's son was named Ruble. And Ruble was Rueben's father. She told me also that, Hiram's wife was in fact named Fannie Clay.
I hope this helps.