One cool site I have found is an interactive map of Pennsylvania Counties over time. It is useful to check out how Pennsylvania evolved over the time frame of the Myers residence in Pennsylvania.
I found a set of 1772 tax rolls for Northampton PA. If you look at Penn Township, a William Myer can be found there, listed as a laborer, not a farmer, and not a gentleman. And that’s important when you’re a colony of England, because free citizens counted, but nobility counted more.
I suspect that Penn Township, Northampton PA, becomes two townships in modern times. The two would be East Penn Township in Carbon County, and West Penn Township in Schuylkill County, PA. But I would like confirmation of that.
Finally, Easton PA has a genealogical library that will do research for you by mail. But it comes with a cost. $40 for the questions you want answered. Tempted to ask them to trace William Myers back to 1752 on tax/land rolls, if possible.