Without even looking at my data, I can say on the face of this that the two-month later dates in all of the examples are probably the correct dates. And that is based on the principle (unless otherwise found in the context of dates of the Quaker meeting notes), that the Quakers held onto the Old Style of dating (and I'm not talking social here) previous to 1748 where the new style of dating was mandated by law. That is, for the education of any readers out there who are not familiar, it used to be that the first month of the year was not January. Instead, the first month of the year was March, to the effect that where some records previous to 1748 state the person was born, e.g., the 1st mo. 7th of 1728, it would mean March 7, 1728, not January 7, 1728. It is apparent to me in reading old secondary sources, that sometimes even the researchers in the 1800s were not knowledgable of that basic fact and would take the 1st mo. 7th of 1728 as "January 7, 1728" and then publish it in their authoritative writings. And then people subsequently relied on the wrong dates in that seemingly authoritative publication.

However, the reverse error can occur when someone is reading a secondary source and they see a date written out as 1st mo. 7th, 1728 written in the New Style, and presume it is the old style and subsequently add two months to what they have mistaken as an Old Style date, and then they are erroneously two months ahead.

Can you tell me which it is? A reference to the actual dusty old original meeting book held at the Archives in Pennsylvania, examined in the context of all the other dates mentioned that year, would be the only reliable verification that I can think of.