Howard Coray witnessed JS translate with "the Seer's stone."
Howard Coray letter, Sanford, Colorado, to Martha Jane Lewis, 2 August 1889, 3–4, Howard Coray Holograph, MS 3047, Church History Library
These gifts are to confirm those that believe—not make believers—I have studied the Gospel as revealed by Joseph Smith and wondered if it were possible for any one unaided by the spirit of God to have revealed such a system of salvation and exaltation for man. My conclusion is that in the negative. I sat and listened to his preaching at the stand in Nauvoo a great many times when I have been completely carried away with his indescribable eloquence,—power of expression– speaking as I have never heard any other man speak– I have heard him prophesy many things that have already come to pass, I have seen him translate by the Seer’s stone I have been was present when he received a revelation on priesthood; he blessed me and prophesied that on my head, which has been litterally fulfilled, and I have seen him by the aid of the Spirit of the Lord, as a prophet raised up to usher in the dispen=sation of the fullness of times...
This technically does not mention the Book of Abraham, but Coray was baptized in 1840. Joseph's previous translation projects (i.e., Book of Mormon, JST) were complete by this time. While Coray could be referencing another instance of translation (or perhaps just exaggerating), it is likely a reference to the Book of Abraham.