Aladdin have produced 18 different models since 1909
They were licenced to be produced in Englad in 1922 This means that the Lamps most likley to be found in the UK will be from No 11 and Super Aladdin on.
The No 23 Lamp is still in Production in USA and available in the UK as a new Lamp

No 1    May 1909 to August 1910
No 2   September 1910 to December 1910 
No 3   January 1911 to August 1912
No 4   September 1912 to August 1913
No 5    September 1913 to August 1914
No 6    September 1914 to Jult 1917
No 7     August 1917 to Jult 1919
No 8     August 1919 to August 1920
no 9     August 1920 to August 1922
No 10   May 1921 to August 1922
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No 11    September 1922 to May 1928
No 12   May 1928 to April 1935
No 14   Super Aladdin Produced in the London Works
A          May 1932 to December 1932
B          Febrary 1933 to September 1955
C          October 1955 to April 1963
21c      May 1963 to December 1969
23        December 1969 onwards