When viewing the sale, Vale of Glamorgan furniture dealer John Williams and his business partner Sue Teesdale spotted a secret drawer to a George III inlaid and crossbanded mahogany chest.
"We noticed the drawer, but we didn't make much of it because we didn't want other bidders to realise it was there. I knew it contained a stash of papers but I had no idea what they were. Everyone else missed it," said Mr Williams.
When he got the chest home, he was pleased to find that the drawer contained numerous drawings by Sir Kyffin, including various studies of daffodils in red ink, a sketch of a horse, and a design for an anchor. It also included ephemera - correspondence with friends and admirers, newspaper clippings and bank statements.
It also contained a number of military buttons from Sir Kyffin's old regiment, the Royal Welch Fusiliers, and a group of Argentinean peso coins that probably date from when the artist visited descendants of Welsh settlers in Patagonia in 1968 and was awarded a Winston Churchill Fellowship to study and paint the people there.
The dealer has consigned the items to Colwyn Bay auctioneers Rogers Jones who will sell them as one lot in The Welsh Sale on September 22, with an estimate of £1000-2000.
As for the chest, after being restored to its former glory, Mr Williams was taking it to the Antiques Fair of Wales at the weekend with a £3500 price tag.
If it fails to sell it can be found at his shop in the Vale of Glamorgan Antiques Centre. Altogether, it is looking to be a nice find for Mr Williams, considering he purchased the chest and contents for less than £500.
