Here's what WFT Vol 148, Tree 668 has on James Green Branscomb:
Born: WFT Est. 1699-1739
Died: WFT Est. 1712-1818
Father: John Branscombe
Born: WFT Est. 1669-1698
Died: WFT Est. 1723-1783
Marriage: WFT Est. 1695-1738
Mother: Unknown
Born: WFT Est. 1678-1701
Died: WFT Est. 1723-1789
One other child - James' brother Richard Branscomb Junior, born 1720 Edge Barton, Devonshire, England. Don't know how he carried the "Junior" designation with a different name than his father. Quite a bit of info on Richard's descendants. Let me know if you want anything more.
Good luck.
Ralph