I have a copy of the 1981 Mayflower Ancestral Index. They have Mercy and Benjamin Whitney listed. It is my understanding that the Mayflower Society will no longer accept this index which they published as proof of lineage. Evidently there were a number of mistakes in the past. I do not know what, if any, credibility they give to the index but if you want the index numbers for your ancestors I would be happy to look the up for you. I am also descendant of Samuel Hinckley and Mary Freeman.