And, 70 x 70 = 4900. Thing about this, is without further information in the puzzle, it could be an author's inside reference that doesn't fit into the puzzle per se. I think there are several of those (like Stockwell's birth year being on the shelf p. 30, and "my poor PELt" and "PEL" found using a border code, sad references to their father, who died, etc.).
Good to keep in mind, in case something else pops up.
Free is the best deal!
"The Scarlet Cloud Approaches"
"Time is of ten a one-way street"
..........Go 5 X 5..........