East Anglian-based auctioneer Cheffins are due to sell one of the most important collections of rare International tractors in the firm's April Vintage Sale.
The Dave Boyles International collection will go under the hammer on April 22, and is expected to generate in excess of £80,000.
There will be 23 international tractors offered, many of which are rare models, including unusual four-wheel drive conversions of standard tractors by makes such as Country and Roadless.
The rarest tractor in the collection is an International 614 Roadless front axle conversion, believed to be one of only five examples every built, which is expected to sell for up to £14,000.
Notable mentions in the lot include a 1969 International 523 4wd, a 1969 International 634 All-Wheel Drive, an International 3588 'Snoopy', a 1968 International 634 Roadless front axle conversion, and the sought-after International 614 with Roadless front axle.
Oliver Godfrey, director of Cheffins auction house, said: "Dave Boyles from Lincolnshire is well-known on the vintage tractor circuit and he has decided to cash in his pension and offer these rare and exciting tractors to the open market.
"We are thrilled to be involved in the sale of the collection and expect a number of machines to sell for top prices.
"The International 3588 'Snoopy' is likely to generate a good deal of attention and we will be interested to see how well this sells, bearing in mind we have only sold one of these examples in the past 10 years."
Anyone who may want more information on the auction should visit cheffins.co.uk, or call 01353 777767.