I found this a fascinating account of the Allings-Allens, but really question its reliability. I am guessing the original source document underwent an OCR scan to create a digital document for online use, but the resulting product certainly has some bizarre spellings, and I'm just not experienced enough to ascertain its accuracy. This document appears to use the word "Alien" and "Ailing" sporadically in place of the names Allen and Alling, even claiming "...the Anglo-Saxon race Ailing is the name of a very ancient town in Denmark..." but I find no record of any such a town, and name searches of Alien and Ailing yield scant results. There are other scattered abberations as well. I'd love to see the original book, though.