In an auction full of rare collectable items related to the 1916 Rising, the trial coin attracted the highest bid.

The hammer fell at €7,200 in Whyte’s auction rooms in Dublin on Saturday but, after adding buyers’ fees and taxes, the final bill comes to around €8,970.

According to Whyte’s pre-sale catalogue, it may be one of fewer than 50 examples that remained unreturned after being issued to various companies and organisations in advance of the introduction of the eventual 20 pence coin in 1986.

Their purpose was to allow the calibration of vending machines, pay phones, and coin meters, but most of the 500 believed to have been sent out were returned to the Central Bank after this exercise.

However, auctioneer Ian Whyte cautions that you are very unlikely to find one of these examples in your old change jar, as they generally weren’t in public circulation.

“The seller had worked for Telecom Éireann and found it among his things after finishing work. Although he did say he might have had a few, and could well have used one if he was short 20p for a cup of coffee,” he said.

The price paid for the rare coin beat the €6,400 final bid for the medal of 19-year-old Patrick Farrell, killed during the Easter Rising.

Also of 1916 interest in Saturday’s sale was a gong from the mess of Richmond Barracks in Dublin, with inscriptions suggesting it was fashioned from a shell casing used to fire at the GPO from the patrol yacht Helga during the six-day rebellion.

A rare trial 20p coin from 1985 went for nearly €9,000 including buyers’ fees and taxes at an auction in Dublin at the weekend

It exceeded the catalogue estimate, when the hammer dropped at a price of €2,600.

Meanwhile, a link to Ireland’s troubled past turned up on BBC’s Antiques Roadshow on Sunday, when a grand-daughter of famous Cork silversmith Barry Egan was astounded to discover a silver bowl’s value.

She had a £700 (€950) valuation placed on the bowl 12 years ago, but the antiques expert Alastair Dickenson told her its rarity makes it worth around £15,000, or nearly €20,500. The hallmark to the base looks very like the usual mark for Cork silver, but the normal three-masted ship sailing between a pair of castles — like in the city’s coat of arms — is replaced with one featuring a two-masted ship. This denotes it as a rare piece of so-called Republican silver.

These were an estimated 60 to 80 pieces made in the Egan factory during the early months of the Civil War in 1922, when damaged and dangerous rail and road connections around anti-Treaty Cork meant Egan’s silver could not be sent to the Dublin assay office fore normal hallmarks confirming its authenticity.