Back in 2010 when Fishing came out, a variety of ships were leaked for purchase on the Test Server. They were all enemy ships (including the Ship of the Line). They were intended for another update in which we could obtain enemy ships as our own, but that update was cancelled.
A dear friend of mine (who wishes to remain anonymous) has provided me access to the only known Phantom ship that was purchased on the Test Server before they were pulled from Shipwrights' catalogs.
Here are the screenshots: