Once they put the c/n on the bottom, the size number moved to the handle and was no longer on the bottom thereafter. You can be confused by one of the RBs inconsistencies that shows and dates a stylized logo HR C/N pan "c. 1924" while on the same page dates HR/size number pans as "c. 1925-1930". The advent of Wagner catalog numbers dates as starting around 1924. It is, however, possible HR/size number patterns continued to be used after 1924, although if you note how high the c/n is on yours (above where the size number was usually situated), it likely demonstrates that existing size number patterns were being revised.
The BB, on the other hand, more accurately dates stylized logo HR/size number pans as "Circa: 1920-1924", and HR C/N pans as 1924 -1935.
Same authors, conflicting info. The RB hasn't been updated since 2001, and even though a new edition of the BB was released in 2011, even it has info that continues to be incorrect.
