"The Darter-Tarter Family" by Oscar H. Darter (publ. 1965) indicates that Balzer was born ca 1750 and died sometime following the making of his will, which is dated 11 Feb 1800.I have no information on Magdalina.What is your evidence for naming her Wampler?
The age problem is one of the reasons that many Darter/Tarter researchers doubt that Balzer is the father of John Tarter (ca 1760/1770 - ca 1849).The other is that Balzer names all of his living children in his will, but does not name John (see transcription http://www.chronography.com/rainwater/owills.html#btw)http://www.chronography.com/rainwater/owills.html#btw).
I am not clear on your reason for assigning 1762 as the year of John's birth, and wonder what documentary evidence you have to support it.My calculation of b. 1760/1770 is based on the 1840 census.