Это пятничное или вы серьезно?

Извините, но не совсем понял - сугубо с оглядкой на историю этой модели и спросил:
ca. 1964-65: original design with short metal knob, two-ply center bar, labelled with code M-5 and "Made in U.S.A" plus either a "SCHICK" or a triangle logo, blank doors, approximate weight 55-g.
ca. 1966: design revised with long metal knob, two-ply center bar, often labelled with code 6-M, "3-2" or "4-2", and "Made in U.S.A" plus either a "SCHICK" or a triangle logo, blank doors, approximate weight 50-g.
ca. 1966: as above, but grey instead of black and branded EVERSHARP with eagle logo.
ca. 1967-68: design revised for 1967 patents, plastic knob, one-ply center bar, often labelled with code 1-M, "PATENTS PENDING", doors stamped "Schick - Schick" or "Schick - Krona" or "Schick - (blank)", approximate weight 38-g.
ca. 1968-76 or later: plastic knob, one-ply center bar, various codes, doors stamped "Schick - Schick" or "Schick - Krona" or "Schick - (blank)", approximate weight 38-g.

All known gold Kronas were of the 1964-65 style. This includes the special bicentennial "Executive Travel Case" sets, which were first marketed in 1965.

Плюс встречал на одном из буржуйских форумах такое разделение по агрессивности :
65-агресивные
65-68- средние
68-77 - мягкие