Jack H. Tod. (1971) Porcelain Insulators Guide Book for Collectors (Unipart Pin Types), hardbound book with lots of information on how porcelain is made, radio-treated insulators, special designs, knicknames, cleaning, and over 50 pages of company history, 205 total pages. Supplement A (Oct. 1972) and Supplement B (November 1973) also included. Supplement B is signed by Jack, $8