I looked at the Phil. Co wills, and there are none that contain the surname Skill, in any way....I also looked on the Philadelphia Yearly meeting records with the same results. If these folks were, indeed, Quakers, there is a very good chance you'll find them in the meeting records where they lived. So, you need to do a little homework and discover what meetings were held in their area and see if you can find extant records for those meetings... the Quakers were prodigious record keepers, a great help to researchers.
Was Samuel married to Patience BICKHAM, who was born about 1733? If so, Samuel was not a Quaker, unless he became one after his marriage.....they married 13 September 1760, at Christ Church in Philadelphia, Pennsylvania, and Quakers MUST marry other Quakers in a Quaker meeting...nowhere else. If Quakers before the marriage, they would not have been Quakers after it...they would have been disowned by their meeting ...in this case, this would be recorded in their meeting records. So, search the local mm records.