Outfitted in full military uniform, Francis Edward de Groot infamously gate-crashed the occasion, swooping in on horseback and slashing with a sword the ceremonial ribbon about to be cut by NSW Premier Jack Lang.

The Irish-born fascist was convicted of offensive behaviour and fined five pounds for the misdemeanour, and so it was that one of Australia's most recognised landmarks acquired one of its more noted controversies.

As the bridge's 90th birthday approaches, however, the call has gone out to anyone with an untold story to share about the Coat Hanger's past or even able to offer up previously unidentified bridge memorabilia.

The request has been issued by tourism outfit BridgeClimb, who is willing to consider each submission for inclusion as an exhibit in its Pylon Lookout & Museum.

CEO Deb Zimmer is convinced some intriguing tales and artefacts are bound to be discovered.

"Everyone has a story that involves the Sydney Harbour Bridge," she said.

"Whether you've scaled to the summit with us, watched it put on a spectacular New Year's Eve fireworks display or simply taken a train ride over it, the bridge has played a part in many people's lives and we're so excited to see what we uncover."

Hot on the heels of the de Groot brouhaha, another lesser known episode in Harbour Bridge folklore took place when Wirth's Circus took seven elephants and a Shetland pony across the fledgling structure in April 1932.

The publicity stunt was designed to promote the big-top show, with records showing toll collectors charged two pence per pachyderm and an unknown amount for the short-legged horse.

Four decades later, a story more Australians might be familiar with unfolded.

Although well before his international rise to fame as Crocodile Dundee, 23-year-old Paul Hogan landed a job as a rigger on bridge in the 1970s.

The future comedic star stuck with the gig for more than a decade, and was still at it when discovered and thrust into the limelight.

With 90 years of history behind it, the iconic arch is brimming with stories to tell, Ms Zimmer says.

To submit them, visit https://bit.ly/3I58a3H

Australian Associated Press