When Stephen Mills took a wild guess to unlock a safe that had been unopened for 40 years, he felt justifiably lucky.

For the more than two decades it had been stored in a small Alberta museum, others had tried to no avail.

“It was a bit of shock. I was just like, oh my, I’m buying a lottery ticket tonight,” he told CTV News Channel on Tuesday.

The one-tonne safe has been in the Vermilion Heritage Museum since the early 1990s, but was originally housed in the Brunswick Hotel, which opened in 1906 and closed in the 70s. According to a museum volunteer, the safe was likely inside until about 1990, when it was moved out to the curb during remodeling. When the museum acquired it in 1992, it was put in the basement where Tom Kibblewhite said “a lot of people” had tried to crack its code to no avail.

When he showed Mills and his family the safe in late May, the visitors were intrigued. “I was like ‘Man, that’s quite a time capsule,’” said Mills, who said he has no experience with opening locked safes but is a “mechanical-minded person.”

So he asked if he could give it a shot. “Certainly, go for it,” Kibblewhite told Mills, expecting the safe to remain locked. “Nobody has done it before, but go for it.”

Mills knelt down and put his ear up to the combination lock “like you see in the movies,” he recalled. The dial read from zero to 60, so he figured he would give 20-40-60 a try. He turned the dial clockwise three times to 20, then counter-clockwise two times to 40, then clockwise one time to 60.

“They were pretty much just out of my head,” he said. “I took a guess and got lucky.”

“I was totally surprised,” said Kibblewhite. While there is nothing of value inside, the contents are “definitely of interest,” he told CTV News Channel.

Inside were old documents, including part of a restaurant waiter’s order sheet and a 1977 pay slip.