I've put off classifying the Allens in the Shearon Cemetery in Sumter Co, AL located between Halsell and Ward for about 8 yrs, but recently started for a friend. You appear to be only one of two people who have mentioned Henry Hood Allen in the Gen Forums or elsewhere.
I'm sure that in the last 8 yrs you have probably found more than I can share with you, but I can point you to about 5 more generations before Henry Hood in your Allen line. In return, I could use anything you're willing to share on HH Allen and his children.
Also seems that HH's wife Mamie C Watkins is a daughter of my wife's ggreat grand aunt, Emmaline Gibson. Anyway....
Henry Hood Allen m. Mary (Mamie) C. Watkins l Benjamin Julius Allen m. Mary Cornelia Wood(s) l Enoch Allen m. Jane Shirly (Sykes?) l Benjamin Allen m. Hulda Parker l Drury Allen m. Nelly (Eleanor) Jarrott l William Allen d. 1789 Mecklingburg Co, VA