Customs are one-off hand-painted versions of existing toys.
Another one-off version was the T.21C, also known as the T.46, which flew in October 1957.
A one-off all-metal version, the P.64 Fachiro III, was further developed as the P.64 Oscar.
B-2 - one-off version with extended wingspan for Charles Lindbergh promotional tour (1 built)
A number of one-off special versions of Ferrari road cars have also been produced, some of which have been commissioned by wealthy owners.
Each model is equipped with Emerson's Wave opening mechanism, aside from one-off versions that lacked it.
A special, one-off version called the 400GT Monza was built by Neri and Bonacini, who had previously worked on the 350GT.
ITV produced a one-off dramatic version of Ryan's book, also titled The One That Got Away, in 1996.
Shortly before the release of the 1995 movie, three new comic book titles were released, followed by a one-off comic version of the film story.
Typically 3D printing is used for prototyping - making one-off versions of items as part of the product design process.