The Director of an Australian State Museum has asked your advice in relation to three objects that are the cause of some concern.

The first object is an Hiberno-Saxon style illuminated manuscript dating from approximately 850 AD. The manuscript was donated to the Australian State Museum by a Benedictine Monastery in Brisbane when it closed 20 years ago. The Australian State Museum has received a letter of demand from a Law firm representing the Notre Dame Priory in Rome, claiming that the manuscript had been stolen from it in 1955, and demanding its return. The donation to the Australian State Museum by the Benedictine Monastery had been accompanied by a sales receipt for the manuscript from a dealer in Rome dated 1 July 1997. The Australian State Museum has managed to contact that dealer, who had provided all the information that the dealer had when she had purchased the manuscript from a French dealer in 1995, including all the Art Loss Register search results. Unfortunately, there was little information about the French dealer from whom the manuscript had been purchased as he had committed suicide after revelations of unethical purchasing in the late 1980s and had destroyed all his records before his suicide. The second object is a double bass made in 1855 by John Devereux, to be used in an exhibition of musical instruments in the museum. The double bass is on loan from a Polish private collector, borrowed following the Museum's successful application as a borrowing institution under the Protection of Cultural Objects on Loan Scheme. The museum has now received two demands for the double bass, one from a claimant who claims that the double bass had been owned by his father but confiscated by the Nazis in Poland in 1940, and another from a creditor of the private collector who demands that the object be returned to Poland or he will initiate proceedings in Australia seeking the seizure and forfeiture of the double bass.

The third object is a painting by Eugene von Guerard depicting a rural scene in Victoria, painted circa 1852. The painting has never been on display, was never in the museum's official inventory, and was only discovered recently in the museum's warehouse. The museum has no record of how it came to possess the painting. During the search for a history of the painting, the museum contacted a gallery in Austria, von Guerard's country of birth, who have now offered to purchase the painting for $500,000. Since the museum estimates that the painting would only fetch half that in Australia, the Director is eager to sell it and wants to know if there are any processes or limitations that would prevent its sale and export to Austria.

Advise the Director, giving a full explanation on all relevant points of law.