Great material and thaks for the response. I'm unsure how to pursue it, however. What comes to mind:
Ludwig or Lewis W Bibler (1741-1778), s/o Johann Franciscus Bibler and Albertina Chalotha Kroh/Grau, was born in Germany about 10 years before the family immigrated to Philadelphia (1751)and thence to Virginia. He's not known to have had a son named Charles or Christopher, so far as I know. His marriage to Barbara/Barbary Unknown is believed to have been about 1772. His 8 children with Barbary range from 1773 to 1793. In 1756, your earliest estimate as to Charles/Christopher's birth, Lewis would been only 15, making it unlikely, but he'd have been 20 in 1761, your later estimate.
I don't think much is known about Johann and family prior to Virginia, though perhaps others have material of which I'm unaware. The St. Andrew's passenger list doesn't include Johann's family. Johann had sons Johann Christian Henrich (1743-?), born in Germany, and Christian Henrich (1752-?), born in Virginia and who married an Anna Unknown. Nothing more is known about those two, so far as I know.
The early Biblers in Virginia sometimes were listed as Pebler, including Lewis. [See Pence Families of the Shenandoah Valley of Virginia, Richard Pence, variously online.]
But I'm rarin' to run with this, if I can see any direction *s*