(NO EXAMPLE OF "DUNHILL" 'within the compass' - January 3, 1919 to May 20, 1919)
EXAMPLE 'equal to the compass' May 21, 1919 to January 1, 1920
Stampings:
[S1] A [encircled ---] DUNHILL [in an arch /] LONDON [‘l’ & ‘n’ meet ends of arch]
[S2] MADE IN ENGLAND [/] "INNER TUBE" [/] PATENTED MARCH . 9 . 15 [---] 54
Pictures:

Additional Pictures:
A model "45" & a model "38" with identical nomenclature except for model number:
A Dunhill advertisement from a 1920 issue of Vanity Fair pictures a pipe having identical [S1] nomenclature: