Righteous indignation against the corrupt shogunate made Oshio Heihachiro (Wikipedia), government official in Osaka himself, to organize an uprising in 1837. In the previous year, he had drafted a 2000-character manifesto and had it printed secretly. In order to prevent the woodcutters from reading the content, the woodcut was prepared in 32 divisions, so that each piece looked like nothing but a cipher. In the image below, divisions between woodcut blocks are clearly seen as horizontal spacing. (I learned of the episode in an epic manga by Minamoto Taro, Fuunji-tachi (Wikipedia, Wide edition, vol.14, p.212).) Although the prematurely started uprising was suppressed in a day, the manifesto of Oshio, who was also a scholar, was hand-copied and circulated widely.
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Here is an image of the manifesto preserved in Joshoji (成正寺), the temple also housing Oshio's tomb and a memorial, as well as the woodcut reproduced in 2006 (関西・大阪２１世紀協会「なにわ大坂をつくった100人 第20話 大塩平八郎（1793－1837年）」).
The copy shown in the photo on an auction site is in the form of a scroll and appears to be a different copy from the same woodcut (なにわ歴博ブログ ～等身大の学芸員生活～).
The image below is taken from the National Diet Library (image, catalogue, 大塩中斎先生天保救民告文).
The image at another auction site seems to be a contemporary handwritten copy (『委託HK◇大塩平八郎檄文 巻子装 天保八（1837）年（思想家 陽明学 大塩中斎 近世古文書 大坂 天保の大飢饉 書状 幕臣 大塩平八郎の乱）』).
Other copies (early printing? in different layouts) are found here (大塩平八郎檄文) and here (大塩平八郎檄文).
A transcription is found at 本山美彦「土佐堀川が育んだ改革者たちの言葉（6）」 (with modern translation and annotations) and also at 資料385 大塩平八郎の檄文.
