The death of an eccentric West antique dealer has revealed an Aladdin's cave with a difference – an untidy hoard resembling a scene from 60s classic comedy Steptoe and Son.

John Vosper, whose customers included Princess Anne and the late Princess Margaret, had squirrelled away the vast arsenal of antiques at his home in Stroud, Gloucestershire, with many not having seen the light of day for at least 18 years.

Experts were amazed by the variety, quality and potential value of the secret collection, which had gathered dust since Mr Vosper's retirement in the late 1980s.

Gems uncovered included a large collection of Royal commemoratives, many books of local interest to Gloucestershire and the Cotswolds, including one featuring a glossary of the local dialect, and a vast silver collection.

Now the huge array of clocks, oil lamps, books, china, glassware, silver, medals, postcards and furniture has been catalogued, in 457 lots, and will be sold on December 11 at an auction expected to raise thousands of pounds.

"It is an eagerly awaited sale and it will contain antiques, collectables and curios to appeal to every taste," said a spokesman for Simon Chorley auctioneers of Prinknash, near Gloucester.

"The auctioneers had to fight their way through piles of clocks, brass and oil lamps as they catalogued the sale in what looked like a scene from Steptoe and Son.

"This is testament to the huge number of sales that John attended during the heyday of the house sale in the 1970s and 1980s."

Simon Chorley, who knew Mr Vosper well, said: "The antique world lost one of its greatest characters when John died, aged 86, after a short illness on September 8.

"In the last half of the 20th century, he attended thousands of sales throughout Gloucestershire and the surrounding counties.

"Tens of thousands of people visited Vosper's antique shop, Priory Antiques, in Minchinhampton's market square and it boasted royalty among its attendees."

One of the highlights of next month's sale, he said, will be an impressive lidded trophy won in 1913 by Captain Percy E Lambert – one of the best known motor racing drivers of his era.

Lambert was the first person to cover 100 miles in an hour which he achieved at Brooklands on 15 February, 1915 in his 4.5 litre-side valve Talbot.

Mr Chorley said: "This record was soon broken and Lambert promised his fiancee that he would give up his pursuit of records after one last attempt.

"On 21 October, 1913 while on track to reclaim the record a tyre disintegrated causing the car to crash and roll.

"He died en-route to hospital and is buried at Brompton cemetery.

"This lot is particularly poignant in that it was won after he broke record and before his untimely death. It is a safe bet at £500-700."

Public viewing of the collection is on December 9, between 10am-7pm and December 10, between 10am-4pm.