"To be crassly profane, you see how primitive and simple it is, and it has this vast, extrarodinary value," he said.
The book is in remarkably good shape considering its age and the use it surely got in its early days. The pages are brownish but not brittle.
The book was rebound, in black leather, in the 19th century. Someone, likely an early owner, used a blank page toward the front to write down some business records. The Boston Public Library, where the book been kept since 1860, put one of its paper nameplates on the inside cover, also in the 19th century.
The Newberry vault — which is really a secured, climate-controlled room within another secured, climate-controlled room — is where the library stores its most valuable treasures, including first editions of "Don Quixote" and of the "First Folio" of Shakespeare's plays.
Also on the table before Redden were some of the material the Newberry will display with the psalm book: items in the library's collection relating to the book's owner, Boston's famed Old South Church.
The church owns two "Bay Psalms" (and also makes a digital copy available on its website). Last December it made the controversial decision to sell one of them to boost flagging finances and help fund building maintenance and charitable work for the United Church of Christ congregation.
"The members voted overwhelmingly … to convert a precious and rare book — an ancient hymn book — … into ministries of justice, mercy and beauty," senior minister Nancy Taylor said in a statement, headlined "Doing a Hard Thing at a Critical Time."
Taylor compared the decision to one the congregation had made in the 1870s to move out of its historic building. Now known as the Old South Meeting House, that building is where Benjamin Franklin had been baptized and the Boston Tea Party had been planned.
The materials Newberry will display Wednesday includes one of two existing copies of a broadside describing the tea party meeting.
"It was being typeset as people left the meeting, went down and threw tea into the water," David Spadafora, the Newberry's president, said in a phone interview.
"Fabulous," said Redden, looking at the tea party broadside. "How wonderful!"
Estimating a price for something like the "Bay Psalm Book" "requires some thinking outside the box," Redden said. "You're comparing it to the sort of greatest objects in any category."
When a copy last sold, to Yale University in 1947, its price of $151,000 "was far and away the most any book had ever brought," said Redden.
At the time, Sotheby's sold a Rembrandt paining for $75,000 and, 60 years later, he said, would sell it again for $28 million. Meantime, in the past decade, the auctioneers sold a copy of Audubon's "Birds of America" for about $10.5 million and of the Magna Carta for $21 million.
"You look at yardsticks elsewhere," said Redden. "Objects at the very, very, very pinnacle of their category are intensely desirable and extraordinarily valuable."
There will be a reserve at the auction, a price below which it will not be sold (typically anywhere from 60 to 100 percent of the low estimate, said Redden). And, as per usual, he would also not disclose what Sotheby's cut will be.
But he figures he'll start the bidding at $8 million, and the sale "will last roughly the same amount of time selling Sue took — maybe five minutes."
Even if a private buyer ends up purchasing it, Redden says he has a "strong suspicion" that it will be given or loaned back to a public institution.
It would be perfect for the Newberry's collection, rich in American history, but a purchase is not likely, said the president, Spadafora.
"Our whole operating budget is smaller than what somebody is probably going to pay for it," he said.
The library, though, has invited collectors and benefactors it thinks might be interested to come take a look Tuesday night, after a media preview in the afternoon and before the public display Wednesday.
It is not impossible, Redden said, to imagine that all this attention might lead to the discovery of another "Bay Psalm Book." It's such an unassuming looking item, a copy or two might well be hiding in plain sight.
"Once this becomes famous again, I suspect a lot of people will be going through old bookshops, attics..." he said. "If they find one, they will have certainly hit the jackpot."