Evolution of dating from 1940 accomodating resistance exercise machines
Dobbs Hats from this period feature the address, at least on the silk hat examples I have seen.Note that below the address the banner reads "The Knapp-Felt Shop," as the primary hats Dobbs & Co.
I haven't seen any Dobbs Derbies or soft hat examples from this period, but they should be similar; however, it's always possible they omitted the address from them.The silk hats I have seen did not have factory labels, so I have yet to ascertain what these early labels looked like.Crofut & Knapp allowed the United Hatters of North America to place their label in C&K hats from 1896 until 1909.NOTE: This guide will utilize liner tips and factory labels, and to a certain extent, sweatband stamps, to date Dobbs hats to within a decade, or within a few years, as the case may be. There are multiple variation of all liners, labels, and stamps used throughout the years, and this guide only touches on a few that seem to be common.The easiest method to date early Dobbs hats is through the Dobbs crest on the liner tips.
Here is a liner style that was first used in 1922, and may have been used into the 1930s. Note that in the trademark filing and the first physical example, on each side of scrolling banner the addresses 620 (on the left) and 244 (on the right) were used.