Martin Harris gives account of his experience as a BoM witness and affirms his wife hefted the plates.
Edward Stevenson, "Testimony of Martin Harris, 1870," MS 4806, Church History Library
Previous to my being baptised I became A Witness of the Plates of the Book of Mormon in 1829 in March the People Rose up & united against the Work gathering testimoney against the Plates & Said they had testimony Enough & if I did not Put Joseph in Jail <& his father> for Deseption, they Would me So I went from Waterloo 2.5 mls South East of Palmyra to Rogerses Suscotua [Seneca?] Co. N. Y. & to Harmoney, Pensylvania 125 & found Joseph. Rogers unknown to me had agreed to give my wife 100 Dollars if it was not A Deseption & had Whet his Nife to cut the covering of the Plates as the Lord had forbid Joseph exhibiting them openly Martin's Wife had hefted them & felt them [ the gold plates ]3° under cover as had Martin &
Transcript taken from Larry E. Morris, A Documentary History of the Book of Mormon (New York, NY: Oxford University Press, 2019), 297–298.