Pratt gives reports of the plates including the script engraved on them and their dimensions.
Parley P. Pratt, "Discovery of an Ancient Record in America," Millennial Star 1, no. 2 (June 1840): 30
The record consisted of a large volume, in the Egyptian language, engraven on plates of gold. The plates were each about 7 by 8 inches in width and length, being about the thickness of common tin. These were engravings on both sides, and a volume of them were bound together like the leaves of a book, and fastened at one edge with three rings running through the whole. The volume was something near six inches in thickness.