A great example was a signed photograph of boxing's first black heavyweight champion, Jack Johnson, which took £2200 atPlymouth Auction Roomson September 4 (estimate: £1000-2000).
The lot also featured a collection of five original postcards showing Johnson before and after he lost his title to Jess Willard in April 1915, in a fight actually held in Havana, Cuba.
So how did these items end up being sold in the West Country?
Well, for a start it was consigned by Christopher Nickols, who lives in Oreston, part of south-west Plymouth across the river Plym. It turns out that his grandfather's sister - a dancer formerly from Plymouth - was present at many of Johnson's fights.
The 14 x 10½in (36 x 27cm) photo was given to her and her husband by Johnson after they became personal friends of his, and she sent the postcards to her family back home.
"The key figure in establishing the provenance is my grandfather's sister, Kitty (or Kathleen) Zanazzi," said Mr Nickols. "She was a dancer in the former Palace Theatre who, at 18, ran away to Paris to dance - we think at the Folies Bergère. Kitty then decided to seek fame and fortune in America and sailed by liner to New York. During the voyage, she met and fell in love with wealthy, dashing Mexican Miguel Guiterias, who was a perfumer and chemist.
"They married and settled in Havana, in Cuba. Miguel was a friend, mentor and benefactor to Jack Johnson, and the photograph was taken for him. It is signed 'To my friend MG (Miguel Guiterias)'. As we understand it, Miguel and Kitty were present at each of Johnson's bouts, and Kitty used to send postcards home to my grandfather featuring images of the fights."
One postcard, dated April 8, 1915 - three days after Johnson's defeat - reads: "The knockout of Johnson. Him and Willard are good friends now. Jack Welsh was referee. Kitty."
Mr Nickols said his grandfather, Herbert 'Ted' Zanazzi, was well known in Plymouth and a major figure in the Plymouth boxing scene. "Much of what was sent home from Kitty was given to local boxing clubs and the British Boxing Board of Control. We are left with the photo and the postcards," he added.
Auctioneer Paul Keen said: "A commission bid of £1100 allowed us to start the sale at the reserve of £1000. Most of the bidding was from local collectors sitting in the room, inlcuding a Plymouth family who are keen boxing enthusiasts and in fact bought the gold boxing belt at our last auction for £7500. However, they were soon outbid around the £1800 mark when two of three phone lines battled it out to take the lot to £2200."
It was bought by a London-based Asian art dealer, who personally collects items of Americana.
Johnson fought professionally from 1897 to 1928, and had 114 bouts, winning 80 - 45 of them knock-outs. In 1908 he became the first African American to win the world heavyweight crown when he knocked out reigning champion Tommy Burns.
The signed portrait had a narrow escape during the Second World War. Mr Nickols said: "The photo used to be on the wall in gran's parlour, but during the Blitz a bomb went off nearby. It fell off the wall and broke the glass, causing slight damage. But it is a wonderful image."
The buyer's premium was 16.66%.