The Royal Seal of King Charles II - discovered in an Irvine plumber's yard - has now been handed over to North Ayrshire Heritage Centre in Saltcoats.
The stone relic, almost certainly part of Irvine's old Tollbooth which was demolished in the 1860s, will now be cleaned, hopefully for restoration if possible, then put on display.
It is likely to end up in Irvine's Townhouse, where the Tollbooth once stood.
Irvine historian Billy Kerr, accompanied by Tommy Goddard, brought the heavy stone, which dates back to the 1600s, to Saltcoats today (Wednesday) where it was received by the Heritage Centre's Louise Allan.
Louise said: "We will look into it and see if restoration is appropriate.
"Sometimes it is best to leave things as they are. It was obviously damaged from being outside and I am so glad Billy thought of bringing it to us."
The relic, which has been damaged over the years, was discovered recently at Andrew Hood's Plumbers, a long-established Irvine firm.
Craig Hood, who took over the firm when his father Andrew died 42 years ago, contacted Billy, who set out to identify the mystery object.
After much research, Billy realised it was the seal of King Charles II - and was almost certainly part of Irvine's old Tollbooth.
Andrew Hood was a former president of Irvine Burns Club.
Craig said: "My father told me about it years before his death. It had been wrapped in bubble wrap all this time. We had no idea where it came from.
"I am glad it is now going somewhere they can look after it, preserve it and allow people to see it."
Billy added: "It had been in the shed for at least 40 years, so he was wondering what to do with it.
"His father said it came from the Tolbooth that was demolished in the 1860s, so I went along to have a look at it.
"I took a few photos, went home and did a bit of research.
"After a few days of banging my head against a brick wall I stumbled across what this was - the coat of arms of Charles II.
"This stone would have been on display in the Tolbooth, probably a courtroom piece.
"Sadly this small part of history is now a sorry sight, but it did once belong to the Royal Burgh of Irvine.
"Charles II had similar coats of arms, and this one was his when he was in Scotland."
Charles II's father, King Charles I, was executed at the end of the English Civil War.
His son was proclaimed King of Scotland in January 1651, and tried to regain the English throne, but was defeated by Cromwell's Roundhead forces and fled to the continent.
After Cromwell's death in 1658, Charles II was finally proclaimed King of Scotland, England and Ireland in 1660.
He ruled until his death in 1685, when he was succeeded by his younger brother James (James II of England and King James VII of Scotland).
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