I live in Raleigh and am also an Allen descendant.My Allens are from Middlesex Co, VA (1671); Essex Co, VA (1700's);Spotsylvania Co, VA (1783); Louisa Co, VA (1770's); Granville Co, NC (1770's - present).My phone number is 919-782-2509.
Acccording to THE FORMATION OF THE NC COUNTIES, 1663-1943, Granville was formed in 1746 from Edgecombe; Bute was formed in 1764 from Granville; Warren was formed in 1779 from Bute; Franklin was formed also in 1779; Vance was formed in 1881 from Granville, Warren and Franklin.
The districts you mentioned - Nutbush, Sandy Creek, Fishing Creek may have been in Granville, as these are districts listed today.The Sixth, River & Snow districts could be in Franklin or Warren Counties.
I hope this helps.
You realize that prior to 1750, Granville went all the way to the Pacific Ocean.