There are two passenger pigeons at Horniman Museum in London. This one is in Birmingham. Even better, the Birmingham Museums have made the image freely available in their Digital Image Resource.
Based on its museum accession number (1998Z29) this specimen was re-numbered in the 1990s and all information on when or where this specimen was collected has been lost. According to their records, the museum has another passenger pigeon (1954Z1.744), part of the WR Lysaght collection, which Birmingham obtained in 1954. Lysaght had acquired most of his collection in 1912 or 1913 from another collector, E.M. Connop. There is no other information associated with this specimen, either.
References:
Watson, Phil 2010. Birmingham Ornithology Collections Part 2 – The W R Lysaght Collection of Birds. Birmingham Museums and Art Gallery.
Watson, Phil 2011. Birmingham Ornithology Collections Part 5 – The Collection of Foreign Birds. Birmingham Museums and Art Gallery.