Blue Bird
Models and s/n	Y	M	D	Remarks	Ref.
Standard Manual
To 218000	1935				6
218001	1936				6
240001	1937				6
280001	1938				6
290.001 to 300000	1939				6
500000	1950				6
541001	1951				6
580001	1952				6
650001	1953				6
712501	1954				6
775001	1955				6
837501	1956				6
900001	1957				6
960001	1958				6
1030001	1959				6
1080001 to 1100000	1960				6
Dynacords
2000000	1960				6
2011001	1961				6
2026001	1962				6
2034001	1963				6
2053001upwards	1964				6
Portables
Model 20-Ace Models
130000	1931-1932				6
160001	1932-1934				6
190001	1935				6
220001	1936				6
245001	1937				6
277001	1938				6
290001 to 310000	1939				6
500000	1951				6
551935	1952				6
650001	1953				6
712501	1954				6
775001	1955				6
837501	1956				6
900001	1957				6
960001	1958				6
Over 1030000	1959				6
Model 30
960001	1958				6
1030001	1959				6
1350001	1960				6
1400001	1961				6
1506001 to 1516000	1962				6
De Luxe Model
250000	1938				6
300001	1939				6
500000	1950				6
541001	1951				6
580001	1952				6
650001	1953				6
712501	1954				6
775001	1955				6
837501	1956				6
900001	1957				6
960001	1958				6
1030001	1959				6
1150001	1960				6
1207001	1961				6
1245001	1962				6
1271001	1963				6
1305001 upwards	1964				6