Francis Bacon works discovered on the backs of amateur paintings may sell for at least 100,000 pounds ($154,000) when they come up for auction next month.

The works, showing background and architectural elements from what appear to be “Pope” paintings, will be sold by Ewbank’s in Guildford, southern England, on March 20.

The Heffer Gallery of Cambridge supplied art materials to both Bacon and a local painter, Lewis Todd.

“It is not known how Bacon’s used canvases came to be at the gallery in the first place,” the auction house said. Bacon favored painting on the unprimed reverse. Heffer provided rejected examples to Todd, who cut them up and painted his own impressionist compositions on the unused fronts, Ewbank’s said.

Todd, who died in 2006 at the age of 81, was a caricaturist for the Cambridge Daily News. After World War II, he was encouraged to paint by Heffer.

Six paintings by Todd -- each bearing the ghostly fragment of a Bacon on the reverse -- have been entered for sale by unnamed private individuals.

Five have been confirmed by the Francis Bacon Authentication Committee. Paint samples have been analyzed by Northumbria University and conform to those used by the artist in the 1950s and 1960s.

Pope Clothing

A 1958 still life by Todd with the leg of a chair and a glimpse of ecclesiastical clothing on the reverse is one of two paintings estimated at 25,000 pounds to 35,000 pounds. A sixth canvas hasn’t yet been authenticated and has a lower estimate of 5,000 pounds to 10,000 pounds.

“I would have thought 5,000 pounds would have been enough,” the London-based dealer Richard Nagy said in an interview. “But people love celebrity and will pay a lot for something that has a little of a famous person’s DNA on it.”

In 2007, Ewbank’s sold a group of rejected and damaged Bacon paintings retrieved from a skip outside the artist’s London studio by electrician Mac Robertson. Valued at about 50,000 pounds, the collection sold for 1.1 million pounds.

Goldfinger DB5

A gadget-packed Aston Martin that was used to promote the James Bond films “Goldfinger” and “Thunderball” is being sold by a U.K. car dealership, priced at 3 million pounds or $4.6 million.

The mid-1960s silver coupe, one of just four original 007 Aston Martin DB5s, is in the showrooms of the Cobham, Surrey dealer R.S. Williams Ltd, a specialist in the marque.

The company would not identify the Swiss seller. The car’s chassis number matches that of the one owned by businessman Thomas Straumann, Bloomberg reported. He acquired the car in 2006 for 2.7 million Swiss francs ($2.9 million now) and had it restored, according to a 2010 report in Bilanz magazine.

In the 1964 movie “Goldfinger,” gadget-master “Q” tells a disbelieving Bond to pay attention before introducing the car’s “rather interesting modifications.”

These include an ejector seat, retractable machine guns, rotating number plates, a bullet-proof rear window, electronic tracking and an oil slick sprayer.

This Swiss-owned DB5, chassis number 2008, has been restored and features many of the devices, activated by switches in the central armrest. The car had been acquired by its owner from the Smoky Mountain Museum in Tennessee, R.S. Williams said in its catalog.

“The Bond films made Aston Martin a famous marque,” Richard Williams, the dealership’s managing director, said in an interview. “Far fewer people would have heard of the cars if it hadn’t been for 007.”

‘Goldfinger’ Connery

Another version of the Bond DB5, driven by Sean Connery in “Goldfinger,” was sold by RM Auctions in London for 2.9 million pounds with fees in October 2010.

Billed at the public sale as “the most famous car in the world,” chassis number 1486 attracted little competition and was bought in the saleroom by the Ohio-based collector Harry Yeaggy. The presale low estimate had been 3.5 million pounds, based on hammer prices.

The original prototype used in the filming of both “Goldfinger” and “Thunderball” had its gadgets removed and was stolen from a hangar in Florida. It has never been found. The fourth car, also used for promotional purposes, is in Dutch collector Evert Louwman’s motor museum.

This latest 007 DB5 has been on the market for three weeks.

“We’ve had one offer so far, from an English collector, that was too low,” Williams said. “A person who collects important things will eventually find us.”