The Tanner's 1977 book, Did Spalding Write the Book of Mormon? is not available for free online. Also, Dan Vogel, back in 2007, interacted with proponents of the various Spalding theories of Book of Mormon origins on a thread entitled
DAN VOGEL DISCUSSES THE SPALDING/RIGDON THEORY
While Dan cannot exegete scripture (ancient or modern) to save his life, he does a great job at refuting the common evidences Dale Broadhurst et al., provide to support the Spalding theory.
I make this post to show that the Spalding theory can be easily refuted by simply referencing works from critics (Vogel) and anti-Mormons (Tanners), although there have been other excellent refutations by Latter-day Saints, such as my friend Matt Roper.