Yes, Master locks definitely have a data base of codes somewhere that some people have access to. About a year ago I listed a lot of 6 antique brass master locks on e-bay that had dials type locks. I did not have the unlock codes to any of them and was selling them "as is" in a lot.
Some kind gentlemen looked at my listing photos and saw the serial numbers of the locks. He then sent me a e-mail with unlock codes to all the locks I had listed and said, "Now you can sell them for what they are actually worth, and suggested that I bump up my price".
After receiving the e-mail and codes to all my locks listed, I e-mailed him back thanking him and asked how he located the codes. He said he used to be a lock smith, and had vintage manuals to all of the master locks made.