Yale version of the Branford knob, P3030F shown on page 18 of the 1893 Branford catalog. Note the tab for the Yale triplex spindle. Most likely made after Yale bought Branford. This catalog indicated Yale & Towne as the leasee of Branford Lock Works.L-15200,L-15210and L-15220 are very similar. L-15200 has a smaller center dot and L-15220 has the largest number of flutings.