I'm not familiar to a Jefferson Harold Halfhill, but there is Thomas Jefferson Halfhill buried in Bennett Lane Cemetery, in Rosendale, Andrew Co., Missouri who was married to Elizabeth Barrett, who is also buried in Bennett Lane Cemetery. I have visited his grave & I have pictures of his headstone. Elizabeth is also buried there according to cemetery records and from her obituary, but her grave is unmarked. Their births and deaths correspond to the dates you list. I also have a copy of Thomas Jefferson Halfhill's will leaving his estate to Elizabeth Halfhill, Elmer & Elza, James and Lewis Halfhill.