The late Andres Nurmela, who died in January 2021, had left his collection to the shop in his will and following his death the executors informed the shop of the bequest.
Nurmela, who lived in Okehampton, had told the then manager Val Sharpe of his plan last year.
Oxfam, which sells both books and music, now plans to sell the 2300 books through their shop and online. A special Gothic themed window display was created dedicated to the bequest by Sue Bamford from Plymouth College.
The team at the shop said: “Andres Numela, a valued customer for 10 years, sadly passed away in January. He very generously bequeathed his antiquarian collection, acquired over many years, to us.
“There are far too many to put out altogether so we will be drip feeding them onto the antiquarian shelves over the coming months. Some will also be in the glass cabinet opposite the shelves.”
The books range in value from £20 to more than £1000 and include a first edition, fourth impression Mrs Beeton’s Book of Household Management from 1866.
Shop manager Robin Neave, added: "Our research volunteers have researched and priced the books. However, at a later date, we may decide to involve a local auction house.”