On the end flyleaf of a copy in The Library of Congress there is an autograph bill of sale in Hebrew signed by Gershom Soncino translated as:
" 'Gershom, the son of Moshe Soncino (of blessed memory), Printer,' and issued to one Moshe ben Shmuel Diena, stipulating that the buyer might not resell the volume for a period of two years. The bill of sale is dated 'the 25th day of Tevet, (5)249 [ = December 29, 1488, here in the city of Soncino' ten days after the printed date of publication.'
Arthur Z. Schwarz, who first brought this to the attention of the scholarly world, suggested that this volume may well be one of the first, if not the first off the press. The colophon date is the day of the 'completion of the work,' i.e. the printing. Some days may have passed before it was ready for distribution. Soncino's signature is his only Hebrew autograph to have survived" (Jewish Virtual Library.org, accessed 12-10-2008, includes images).