27.mm
Feather key fixing, short boss, no holes | 27.mm1
Feather and tongue key fixing, no holes | 27.mm2
Tongue key fixing, two holes in face | 27.mm3
Tongue key fixing, two holes, 1911 short boss |
27.mm3a
Tongue key fixing, no holes, 1911 short boss | 27.mm4
Tongue key fixing, no holes, 1911 full-sized boss | 27.br1
Old teeth², no holes, 1911 boss single-tapped | 27.br5
New teeth², no holes, patent boss single-tapped |
27.ni
Thick steel face, nickel plated, patent boss 50/56t ¹ | 27.br2
Thicker face, turned from solid brass, no holes | 27.br3
Brass disc and standard boss, 50/57t single-tapped | 27.br4
Brass disc and standard boss, double-tapped |
27.br
Brass disc, post-war stamping |