He has been renowned for decades as the lawyer arrested for his part in a daring heist to bring the Stone of Destiny back to Scotland from Westminster.
Now detective work by a retired sheriff has helped shed new light on Ian Hamilton's little-known past as a playwright - after reuniting him with a lost script for a hit play he penned more than 60 years ago.
The 93-year-old retired QC had completely forgotten about a drama he wrote, just seven years after the famous raid on Westminster Abbey, about a Hebridean island which being lined up for a takeover by the Government for use as a rocket range.
However, completely unknown to the lawyer, a full manuscript for the play - which was written around two years before the Ministry of Defence created a missile range on the Hebridean island of Benbecula - containing Finlay's own handwritten notes had actually been held in one of Scotland's national collections for over half a century.
Para Handy star Roddy McMillan and Annette Crosbie, who would go on to find fame in One Foot In The Grave, appeared in the production, The Tinkers of the World, at the Gateway Theatre in Edinburgh, which went on to be broadcast by the BBC and won the prestigious Charles Henry Foyle New Play Award.
Kevin Drummond, QC, had set about trying to track down a copy of the play after asking Mr Hamilton about it and discovering he did not have a copy of the script and was no aware of any being in existence.
Mr Drummond searched the archives of the Faculty of Advocates, which keeps copies of all known works written by members, but drew a blank.
However pursuing a possibility that the National Library of Scotland may have a record of the play in in extensive theatre archive unearthed an original 80-page manuscript.
Further research by Jane Condie, one of the librarians at the Faculty of Advocates, established that the play had been staged over nearly two weeks at the former Elm Row venue in February 1957. It now holds the original manuscript, while a copy has been gifted to Mr Hamilton, who lives in North Connell, in Argyll.
Mr Drummond said: "The National Library of Scotland found a copy in archives it holds of the former Gateway Theatre in Edinburgh.
"It was one used in the staging of the play. It is typewritten, but you can see Ian’s handwriting in various alterations to the script. I was amazed to see it.
"I thought it must have been inspired by the rocket range on Benbecula, but Ian said the play had been written a couple of years before the base was established, and this was life following art."
Mr Hamilton said: "I couldn’t believe after all this time that there would still be a copy of the play out there. It certainly takes me back to see it.
"The recovery of this script is a triumph of research, as well as a delight for me. I must thank my old friend, Kevin, for starting the hunt, and Jane Condie for her skills and diligence and patience, and all who helped her.”
A spokeswoman for the National Library of Scotland said: "We were quickly able to locate the marked-up typescript of Ian Hamilton’s play in our collections of archives and manuscripts.
"We were pleased that its reunification with the script evoked strong memories of the time it was penned and staged.
"Our world-class collections of archives are held in perpetuity, and we encourage people with items relating to Scotland’s literature, history, and culture to talk to us about the possibility of the National Library as a permanent home for their manuscripts, and ultimately, the nation’s memories.”