The Edo/Kantō/Tōkyō Sources
To be presented in rather more detail and commented further ...
1646: Letter from the Rinzai Zen Abbot Isshi Bunshu/Monju (1608-1646)
to a komusō named Sandō Mugetsu (no dates).
The appellation Fuke-shū, 普化宗, is not at all mentioned in the letter.
1677 (Empō 5, 6th month): Reihō-ji document of order rules with 17 paragraphs.
Fuke-shū is not mentioned in these order rules.
1678, January 11 (Empō 5, 12th month, 18th day): "Memorandum" with 3 paragraphs,
apparently issued by the so called Jisha-bugyō, the shōgun's governmental
Temples & Shrines Magistrates, addressed to Komusō shoha, 虚無僧諸派,
"The Various Komusō Factions".
Fuke-shū is not mentioned in this memorandum.
1687: Reihō-ji 11 paragraph document: Document is signed
Fuke Zen-shū sō-honji Reihō-ji. 普化禅宗 惣本寺 鈴法寺,
"Reihō-ji, Mother Temple of The Entire Fuke Zen Sect".
1722: Reihō-ji ordinance.
Fuke shūmon, 普化禅宗, is mentioned in the very first paragraph
in the available reprint version.
1731: Reihō-ji ordinance.
Fuke shūmon is mentioned in the very first paragraph.
So far Undatable Text (as of March. 2017):
As late as 1740? (acc. to Yamato Hōmei).
Keichō no okitegaki (as late as 1740, or, in 1792?).
Fuke-shū is not mentioned.