Hold on, if the elections are really rigged as suggested in the letter, and the real results hidden as they are supposed to be when such an election is undertaken, Do you honestly think that the government was to put this very memo on Paper that is offical, documented, and recorded for the inner circle of the government to see (including the reformists such as Rafsanjani) if it is archived? I think that this paper is one that is not numbered in order to prevent it from being sought out if it is ever needed so and that once it is read by khamenei, it could easily be destroyed without leaving any trail. I have seen several government papers (my Uncle is the head of a department at IRIB, and my documents for their passport also resembles this document) and I think it is quite credible.