Date: August 07, 2018 11:25PM
Craig Criddle and others have been behind the research on who actually authored the BOM... They've used forensic tools whose scientific merit has been established. Craig has posted here in the past.
As for the mummy, it was part of a "traveling show"* that was orchestrated by a man named Chandler; JS's followers arranged to purchase the mummy along with some papyrus that Joseph Smith declared "was written by his own hand [Abraham's] upon papyrus.
This is the definitive book on the subject; its author, Charles M. Larson, was fired from a public teaching job in Utah County for writing it (working from memory, but I'll Google his name; got it). As I recall, he later won a court decision in his favor.**https://www.amazon.com/His-Own-Hand-Upon-Papyrus/dp/0962096326
*Recall that this was the first half of the 19th Century, and "Egypt was a hot topic" (in part because of its "biblical" connections). Mummies, papyrii, and other artifacts were often part of such traveling shows ("Mummy dust" was often promoted as a folk remedy).
**Somebody want to elaborate on this? I'm having a senior moment...