Black case, white non-luminous dial: 1938 - 1942
Black case, black luminous dial: 1938 - 1958
Ivory case, brown luminous dial: 1954 - 1958
The style 1 Spur in Black/Nickel replaced the Fortune model. After World War II, only black luminous was offered. Ivory luminous was introduced in 1954. Pre-war Spur have the alarm shutoff knob at the angled part of the back, near the top. Those we’ve seen post-war have the alarm shutoff knob on the back (the flat part).