"8.  Currently my father has no 37, 67, nor 111 STR marker matches in the US centric FTDNA database. "

Update:  Alex Guess, who is my father's closest SNP test match, completed a 111 marker test and now shows up as a 111 marker match to my father.

Also my father has a new closest BigY match. Alex Guess' closest STR match, last name Adamthwaite took the BigY test.

Based on available data from multiple dna tests, and genealogical records, I currently believe the shared paternal ancestor of my father and the Guess/Adamthwaite line, live around 1300 AD +/- 75 years.  While the shared ancestor of Guess and Adamthwaite lived around 1600 AD +/- 50 years.