Unbound sheets of Hugh Marwick's 1929 book The Orkney Norn were discovered in Kirkwall.
The Norn language - a variant of Old Norse - was spoken in Orkney, Shetland and Caithness.
A project was launched to get the pages bound, and they are now being sold in aid of the RNLI.
The pages were found when George Leonard was selling his family business.
He remembered seeing the sheets as a young boy and found them again on the first floor of the building which had acted as a store for Leonards, a stationery business.
After some practical and financial assistance, the pages were sent for binding.
Local language expert Dr Simon Hall said: "It lists all of the Norn words that he (Hugh Marwick) could find in Orkney during the early part of the 20th Century.
"He found these by going out and speaking to folk all over Orkney.
"He gathered them together and with huge academic rigour put them in to the book, which was a record of everything that was still extant at that point in time.
"If you look at the text of the book today you will see that there are hundreds of words that have fallen out of use but at the same time there are still many words in it that are used today."
Some of the words include whassigo - insincere talk  - and puther, which is to grope about in the dark.
Copies of a historical book are going on sale in Orkney after the pages were discovered in a warehouse more than 80 years after being printed.