Charlotte Jenks Pinkham appears on p. 49 of Sinnott's genealogy and her ancestry is just how you have it (pp. 44-5, 49).I can't vouch for its accuracy, I've never studied the Nantucket Pinkhams and only concern myself with the New Hampshire Pinkhams (i.e. the descendants of John-2).I do know that Sinnott got Richard-2 (who married Mary Coffin)'s placement in the family incorrect.
I've no idea where you can buy the Gen. Dict. of ME and NH, but as a librarian, I have to advocate that you go to a library and use inter-library loan.Or join the New England Historic GenealogicalSociety and they loan that book out.