Yes, trying to find the source not the person who put it in the book. This is weak at best when you have a city and no address or name. No record so you can't even say it was a counter order and only a city given.
What Steve is saying is maybe Allen made a note on who gave him the information and what was the source and then passed it on to David S. I have no idea how this works. I do know TGT is a massive work and it is the only one of its kind. How David will tackle future revisions of it is beyond my comprehension.

The member that I traded the chips to get these AIS chips also has Kenosha,WI on them and nothing else. He also has no idea who started this attribution. It's good to question some attributions since all are not correct.