Found: Saint Sebastien Bound for Martyrdom by Van Dyck

London dealer Lowell Libson sells Samuel Scott drawings to the Yale Center for British Art and Stephen Ongpin sells to four different American museums.

London galleries have been busy selling to museums abroad. As reported last week, it was London dealer Johnny van Haeften who lifted an eyebrow (his distinctive method of bidding) to secure Hendrik ter Brugghen's masterpiece The Bagpipe Player for a record $10.2 million at Sotheby's in New York.

To get it, he had to outbid New York dealer Richard Feigen, who was acting for the National Gallery of Art in Washington.

Van Haeften had more muscle because he had the support of two other dealers – Konrad Bernheimer of Colnaghi's in London, and Otto Naumann of New York. Dealers are allowed to combine forces so long as they notify the auctioneers beforehand.

However, after the sale the Washington gallery must have reconsidered its finances and came back to van Haeften with an offer which has now been accepted.

Also in New York were London dealers Lowell Libson and Stephen Ongpin, who were taking part in a week of special drawings exhibition.

Libson sold a group of 11 drawings by the 18th-century artist Samuel Scott to the Yale Center for British Art for "a high six-figure sum". Ongpin sold to four different museums.

Among them was an American museum which is acquiring a drawing of an angel by Burne-Jones that had been given to the writer Auberon Waugh in 1961 as a wedding present. Ongpin bought it at a country sale of the contents of Waugh's Somerset house last October.

Not all sales to museums can be completed so swiftly. Last March at the European Fine Art Fair in Maastricht, dealer Mark Weiss exhibited a van Dyck painting, Saint Sebastian Bound for Martyrdom, which had been lost to scholars for 200 years.

When it first re-appeared at an auction in 2000, nobody knew its history and some were not convinced it was even a van Dyck. It sold for £333,750 to dealers Nicholas Hall and Richard Knight.

When the two dealers went to work for Christie's, the painting was acquired by Weiss who established that the painting had been given in the 17th century to King Philip IV of Spain, who hung it in the monastic palace of El Escorial, outside Madrid.

How it left there is unknown, but Spanish officials came to view the painting in Maastricht and took a long time deliberating over it.

On Monday, it was announced that the painting had been bought by the Patrimonio Nacional on behalf of the Spanish state for £2.2 million. It is now to hang just where it used to – near the altar in the Prior's Chapter House in El Escorial as part of a scheme originally designed by Velázquez and Philip IV.

Talking of museums, collectors often find them useful repositories for a work before it sells – think of the kudos attached to work that has hung in a major museum.

The most recent example was Edouard Vuillard's The Dressmakers, which sold at Christie's last week for £5 million.

The painting was owned by the Swiss collector and publisher Paul Josefowitz, who lent it for 15 months to the National Gallery in London.

In 2007, Josefowitz sold another painting that had been on loan to the National Gallery which made a record $14 million for the artist, Paul Signac.