What manuscripts today are used to produce the Warsh Qur'ans?

We know there are multiple Qira'at of the Qur'an derived from the original Seven Ahruf in some way. The most popular Qirat, the de facto Qur'an almost anywhere and especially online is the Hafs < Asim transmission. In some parts of Africa they use the Warsh < Nafi' Qur'an. Currently I am trying to obtain the most "authentic" Warsh Qira'at, _I think_ that would mean finding the manuscripts used today to produce Warsh Qur'ans What are they, where are they and are there online scans? thanks