Rolex Big Bubbleback and evolution to Rolex Datejust

The Rolex Big bubbleback series leading to the Datejust consists of the following 

Rolex ref 4467 (solid Gold from year 1945-1949)  
Rolex ref 5030 (Solid gold) , Bi colour steel and gold 5031, 5075, 6031 (from year 1949 - 1950)，
Rolex ref 6075, 6074 (Bi colour from year 1950 - 1953)
Rolex 6104, 6105 (Bi colour modified A296，from year 1951 - 1953) 
Rolex 6304 , 6305, 6309(Pre ThunderBird) (A296，from year 1953 - 1956)
Rolex Datejust 6604, 6605, 6609(Thunderbird), 1600, 1601,1603, 1607, 1625 (Thunderbird) (from 1959 - 1977 onwards using Butterfly movement calibre generation features cal. 1065 and later cal. 1565 and 1575.)

These are the early Rolex Big bubbleback with Date function:

劳力士DATE JUST于1945年推出的第一个型号是4467，4467是现在所有DJ的鼻祖，是世界上第一只自动上弦，带有瞬跳日历的手表（日历在夜里瞬跳切换）。4467是一只大三针手表，日历在3点位，注意当时还没有日历放大镜。4467只有黄金壳型号，尺寸36毫米

Rolex 4467 & 6031 in solid gold

进入到1950年之后，劳力士推出了4467的后续型号，5030, 5031, 5075, 6031。5030和5031, 6031 开始，就增加了钢壳和间金型号。

Rolex 5031 in yellow gold bezel and crown from 1947

Rolex 5075 in rose gold bezel and crown from 1947

Rolex 6031 yellow gold bezel and crown

Rolex 6031 in yellow gold bezel and crown from 1947

Of all the Big bubbleback, I love the straight lugs best as it truly replicate and represents the original bubbleback design from 1947

Rolex 6104 in rose gold bezel and crown

Rolex 6105 in yellow gold bezel & crown from 1953

Rolex 6105 in rose gold bezel & crown

Rolex 6605 (fluted bezel) Steel and yellow gold Datejust 

Rolex 6605 Steel and white gold Datejust

Rolex ref 6605 in 18k gold from 1957

Rolex ref 1601 Wide Boy in 14k gold from 1966

https://www.ancienne.es/en/blogpost/story-vintage-datejust-watches/

L to R : Rolex 6105, 6031,5075,5031

Source: https://www.vetroplastica.it/rolex-datejust-22.html