Joseph Bradley mentions Joseph translating the papyri in the Evangelical Magazine and Gospel Advocate.
Joseph Bradley, Letter, 21 August 1835; rep. "Universalism in Ohio," Evangelical Magazine and Gospel Advocate 6, no. 37 (September 12, 1835): 291
The Mormons have recently bought an addition to their stock of absurdities, in the form of four Egyptian mummies, and a hieroglyphic bundle of characters, which Jo. Smith pretends he can interpret, and says this ancient manuscript is in the same language of the book of Mormon. (alias Rigdon.) Jo. and a few others, more cunning than himself, but less honest (if possible) in religious matters, are now engaged in translating this precious mummy business so that the vulgar may read this new edition of their monstrous faith! Verily, these Mormons must have consciences of elastic gum, and staunch stomachs to swallow all that their leaders bid them! And even this motley, deluded multitude are contributing their mite to our Partialist friends in the work of persecution!