Greetings Mr. Ancient, thank you for your link and valuable documented report between the lines

The text of Ayatollah Khamenei's written response to Istifta (please note, not the response of his Istifta office), which condemns the manufacture and proliferation of nuclear weapons and is referred to as a fatwa, has not been publicly released as far as I know. 

But I said before, This response, which was presented to foreign parties by the official sources of the country, including the nuclear negotiators at the time, is a fatwa. 

It is obvious that the fatwa is only necessary for imitators of reference, and not imitators of other references. 

In addition, the fatwa is a function of time and place and can be changed by the Mufti; But what Ayatollah Khamenei wrote obsessively and pointed out many times is not a ruling of the government that is necessary for all pillars of the system and imitators and even other authorities to follow. In clearer terms, a fatwa is an authority of imitation, but a ruling but an order or absolute ruler is not a jurist. 

Therefore, such information indicating the approval of the letter, menus and orders of the Leader of the Islamic Republic has not been officially communicated to the executive structure and executor of this matter by the Ayatollah's office, as far as I know.