Rotary phones have been around since the 1890's but it was in 1904 that the commonly known ones with the finger holes were invented.  Also known as whitehall phones, as the telephone number for scotland yard was, 'Whitehall 1212' this number was introduced in 1934 and was an emergency and non-emergency number for the public to contact London Metropolitan Police.  
 
These examples were all made around c1940.
 
They are all in good display condtion - they are not wired for modern technology.