Rockwell’s Blacksmith’s Boy – Heel and Toe (1940), which could sell for as much as $10 million, according to Sotheby’s.

Barring a new legal challenge, 13 works from the collection of the Berkshire Museum in Pittsfield, Massachusetts, will hit the auction block next month at Sotheby’s in New York as part of the institution’s effort to raise a total of $55 million. Among the lots are pieces by Norman Rockwell (with a top estimate of $10 million), Frederic Edwin Church ($7 million), Alexander Calder ($3 million), and Francis Picabia ($1.2 million).

The auction house estimates that the lots could bring in between $20.2 million and $28.9 million when they are sold across five sales between May 14 and May 23. The haul from those pieces will be combined with an as-yet-unknown sum that the museum is receiving from the previously-announced private sale of its most prized work, Rockwell’s Shuffleton’s Barbershop (1950), to an institution that has said it will keep it on public view.

Last week, the Massachusetts Supreme Judicial Court signed off on an agreement reached with the state’s attorney general that will allow the museum to sell up to 40 works with the aim of raising $55 million, an amount it has maintained that it needs to right its finances, build an endowment, and make improvements to its building. The plan has been vigorously criticized by museum groups, since industry guidelines typically permit such sales only when funds are used to acquire new work or care for a collection, as well as some who say that the museum has overstated its financial issues.

Under the terms of the agreement, if $55 million is obtained by selling one tranche of work, additional pieces that have been cleared for sale will remain in the museum’s collection. Those other 26 pieces include an Albert Bierstadt, another Calder, and a Thomas Moran. In a news release, the museum said that it hopes to reach the $55 million figure through the sales of the initial 13 works and Shuffleton’s Barbershop.

The big question in determining whether the museum will be able to hit its stated goal is how much the museum actually got for Shuffleton’s Barbershop, one of Rockwell’s masterpieces, which features a group of men playing music in the back of a storefront late in the evening. The museum’s spokesperson said today that she did not know the sale price, and a spokesperson for Sotheby’s, which brokered the deal, said that the number is confidential. A spokesperson for the Massachusetts attorney general did not immediately reply to a request for comment.

When Shuffleton’s Barbershop was set to be offered last November at Sotheby’s, it was estimated at $20 million to $30 million. That auction was scuttled by legal challenges that led the Massachusetts Appeals Court to pause the sell-off while the attorney general’s office investigated the museum’s plans.

With those legal hurdles jumped, the first sales will occur at Sotheby’s Impressionist and modern auction on the evening of May 14, when a Francis Picabia and a Henry Moore will go under the hammer. The highest-estimated lot from the museum, Rockwell’s Blacksmith’s Boy – Heel and Toe (1940), will finish off the round of selling on May 23, in the house’s American art sale.