The sale of a rare 150-year-old Martin acoustic guitar worth $15,000, which was discovered by an 85-year-old New Zealand woman in her back room, has been reported by Guitar World.

And while the sale amount was less than the guitar's appraised value, the funds are going to a good cause.

The 1870s Martin Size 2 Style 34 guitar finds its new owner in former Fender Musical Instruments CEO Larry Thomas. According to Stuff, he bought the vintage instrument this week for $11,000 (approximately $17,000 in New Zealand dollars). Ahead of the sale, New Zealand's Studio 1 Vintage Guitars demonstrated the guitar in a video.

The woman who found the guitar, Margaret Simpson, made the decision to sell the antique after her daughter Jo Simpson was diagnosed with breast cancer. Margaret said Jo's chemotherapy treatment costs $5000 a month. Thomas finalized the sale on Thursday (Dec. 1).

"I saw the guitar online and was curious to know more about it," the business exec, who helmed Fender from 2010–2014, explained. "I reached out. It was then I came to know about the owner, and it being an old family possession. … I hope that this helps the woman continue her cancer treatment."

Read Margaret's story below. See the video underneath. Donate to Jo's treatment this link.

Margaret, an 85-year-old living north of Auckland, had an 'Old Martin Guitar' she was looking to sell. She believed the guitar to date from the mid 1800s. … Margaret had purchased the guitar in the 1960s — from the music teacher at a school in Nelson where she was working. She liked the smaller body size, and its beautiful appointments, and she played and sang with the guitar for many years.

Unfortunately, Margaret's daughter, Jo, has a terminal cancer diagnosis, and is in need of an unfunded chemotherapy treatment so that she can spend more time with her two young boys. … Margaret had hoped the Martin Guitar was worth something, that could be used to raise some funds for treatment.

Jo bought the guitar into us, we took some photos and sent them off to several U.S. experts and Martin historians, who confirmed our initial thoughts that this is a Size 2 Martin, Style 34 from circa 1870. The style 34 appointments include Ivory binding, coloured Herringbone Purfling and Back Stripes, Abalone rosette inlay and Brazilian Rosewood back and sides. Typical 34 style guitars have an ivory bridge, however this example had been ordered with an Ebony bridge. The guitar has been appraised by world renowned experts George Gruhn and Greg Hutton, with Gruhn Guitars putting a value on the instrument at U.S. $15,000.

1870 Martin 2-34 Acoustic Guitar Demonstation

16 Most Expensive Guitars of All Time

10 Strange Instruments Used by Rock + Metal Bands

More From 97.1 KXRX