I only recognised Allborg because of my frequent transits with our ex Open Skies Andovers en-route to Riga/Russia. However, the main picture is indeed 26R; you were obviously short base for t'other one!
I do have quite a few obscure airfields within my files but I don't have a server to put them on; therefore, Open House...
But you're quite correct, there's plenty of chalk in Chitterne!
TCF