The IME 84 was announced and demonstrated to the public on April 12, 1964 at the Fiera Di Milano in Milan, Italy. The Fiera Di Milano in 1964 was an enormous international trade fair, easily on par with the World's Fair.
IME's booth at the April 12, 1964 Fiera Di Milano
April 26, 1964
June 1964 review of the April 26, 1964 Hanover Trade Fair (starting date), where the IME 84 was exhibited.
Discovered by, and kindly provided to MoTET, by Mr. Nigel Tout of VintageCalculators.com
April 27, 1964
The Guardian (England) (Pg. 9)
Evidence of the April 26, 1964 start date of the Hanover Trade Fair
February 28, 1965
September 24, 1965
2nd Annual SMAU Trade Show
The Computer Journal (London)
May 2, 1967
Sales Receipt & IME 86S System Brochure
Hope College Computer Lab
Source: Louis Beaugrand to Calcuseum