The modest cafe is around 45 minutes by foot from the Bossons glacier where the plane named after the Himalayan peak of Kangchenjunga mysteriously crashed.
Mottin said he was lucky to discover the papers when he did because the ice in which they were encased for nearly six decades “had probably just melted”.
Once the papers have dried out, they will join a growing collection of found items from the crash that Mottin has put on display at the Cabane du Cerro.
He said he preferred to share his finds with visitors rather than “hide them in an attic waiting to sell them” — something he said had become a “business” for less scrupulous climbers.
Human remains were found in the area in 2017 that could have come from the 1964 crash or that of another Indian plane, the Malabar Princess, that came down in the same area in 1950.
The most stunning find occurred in 2013, that of a box of precious stones — emeralds, sapphires and rubies worth between 130,000 and 246,000 euros ($145,000-$275,000) — thought to have come from the 1966 crash.