WWR published arguments for plates being authentic.
Welby W. Ricks, "The Kinderhook Plates," Improvement Era, September 1962, 637, 656, 658, 660
A few years ago, two non-LDS professional engravers, Stanley B. Hill and Edward Pwiiski walked into the Chicago Historical Society and asked to view a bell-shaped brass plate known as a Kinderhook plate. Their purpose was to determine whether it had been engraved with a pointed instrument or etched with acid. What they found solved a seventy-four-year-old controversy and put the plates back into the category of "genuine" which Joseph Smith, Jun., had said they were in the first place.