I have some info I found a few years ago.I ordered a copy of PawPaw's application to the Soc. Sec. Bureau.He states on the appl. he was born 2/5/1904 in Guthrie to Charlie Walton Sayle and Nannie E. Bryan.
I also found a record through FamilySearch International Genealogical Index that lists a Dock Bryan born 1871 in Robertson TN to a Gran and Charity Bryan.No further info was listed in this record.Do you think they would have been Mammy's parents?I should ask Dad.I'll get back with his answer.