You may want to rethink your online shopping habits after learning about a rare find recently made by a museum in the UK. According to The Guardian, a volunteer at the National Museum of Computing recently stumbled upon a teleprinter on eBay that was part of a coding device used by top Nazi commanders during World War II. Not only was the museum lucky enough to find the rare machine, but it was able to convince the previous owner to let it go for a bargain.

The seller had the teleprinter listed as a telegram machine, but experts at the museum recognized what it really was and reached out to set up a meeting to see it in person. "The person took us down the garden to the shed and in the shed was the Lorenz teleprinter in its original carrying case," John Whetter, a volunteer engineer at the museum, told The Guardian. "We said 'Thank you very much, how much was it again?' She said '£9.50', so we said 'Here's a £10 note—keep the change!'" Converted to dollars, the museum paid approximately $15 for the piece of history, which would have been used by Nazis to enter communications before encoding them with a Lorenz SZ42 cipher machine.

According to The Telegraph, the Lorenz SZ42 was a more complicated coding machine than the Enigma Machine, which has been the subject of an Oscar-nominated film starring Benedict Cumberbatch. "Unlike the Enigma system, which took a long time to send and receive messages, operators could enter lengthy messages in plain German into the Lorenz teleprinter relatively quickly," Henry Bodkin writes. Cracking the code gave President Eisenhower access to the German army's most important messages, which were sent by and to Adolf Hitler. Historians believe that only 200 of the "unbreakable" machines were manufactured, and most are believed to have been destroyed. A swastika and serial number discovered on the teleprinter from eBay has led researchers to conclude that it was a part of the system used by Hitler himself to communicate with German field marshals.

The NMC currently has one of the cipher machines that were used with the teleprinters on long-term loan from the Norwegian Armed Forces Museum. It plans to rebuild the coding machine with the teleprinter as soon as missing parts can be found. "To do that we have to replace some missing components, in particular the drive motor—and it’s the drive motor that’s our next quest," Whetter said. In a recent tweet, the museum said that it has some "intriguing leads" in terms of finding a motor, so perhaps the project will be completed sooner than expected.

[h/t The Guardian]