I followed that with a search of the term "Miss I F Walker's," and this new advertisement was revealed. In 1875, R. H. Fry, a wholesaler in Central Falls, Rhode Island, was stocking Izannah Walker's dolls. Izannah was also supplying E. W. Billing's wholesale company with dolls in 1875. This advertisement is important for at least two reasons: 1.) Izannah was supplying more than one wholesaler, so her production might have been on an even larger scale than I suspected; and 2.) the term "stocking-head" enters the vernacular in reference to her dolls. This may have been based on the wording in Izannah Walker's patent, which used the term "stockinet." The term "stocking-head" is an addition to the term "everlasting" used by E. W. Billings, and possibly the earlier term "painted cloth doll."
My next step was to search, using the term "stocking head dolls." This merchant's advertisement from 1874 emerged. Incidentally, that search only brought up two distinct results from the entire nation: R. H. Fry's advertisements and Mrs. F. H. Hayward's advertisements. Mrs. F. H. Hayward's 1874 advertisements actually used the phrase first. I believe that she was also offering Izannah Walker's dolls for sale. Since she was in Providence, she may have acquired them from E. W. Billings or directly from Izannah.
Mrs. F. H. Hayward offered me a research rabbit hole to jump down, so, of course, I did and spent a very pleasant afternoon researching her. The results, which are lengthy, will follow in the next post.