Dave, slightly off topic but do you understand his notes on page 83 titled "Lab Worksheet"? I presume its multiple exposures per print with platinum formulaes - ratio method? Would also guess he pre-soaked his paper so could properly register each exposure.
His platinum prints were mounted on aluminum sheets and the aluminum was pin registered. He told me that he did multiple exposures and that each print took him as much as 20 hours to make.