Hi Sandy & Janet:
Sandy: Thanks again for jumping in. I've been off the board for a while and was pleased to see this old thread come alive again.
Janet: I have collected a lot of info on two lines of Hemmings in Northants: One descended from a family group living in Sulgrave (my line) who ended up in Northampton; and the second from a family group in Moreton Pinkney and Eydon. Going back a few more generations, these two lines merge into an earlier group living in Cropredy, Great Bourton, and Mollington.
My hunch is that the John Hemmings you are referring to is descended from the Moreton Pinkney/Eydon group. Failing that, he could descend from another line of Hemmings that moved to Northampton. The name is relatively common in the West Midlands.
Please feel free to contact me if you come up with any other leads.
Regards, rthom