CEJ studio merged with Bertsch and Cooper in 1921, with the new entity going forward under the Bertsch name.  Timmins worked in the Bertsch studio from the time of the merger until Young & Timmins studio was established in late 1922.  Below are examples of Timmins’ work during the Bertsch period.  Harry’s illustrations for Bertsch have a penant symbol under the signature.  The Sellers ad below is not signed, but others in the series are.  The Sellers ad below was shown in the 1923 Art Directors Club Second Annual of Illustrations for Advertisements in New York City.  The Arkansas Soft Pine ad below is also not signed.  This ad was shown in the 1924 Art Directors Club annual.  A number of prior Arkansas ads were done by Bertsch, so most likely Timmins did this one while working for Bertsch.