Just over ten years on, he is playing to full houses alongside legends of British comedy at a packed West End theatre in the stage re-boot of Only Fools and Horses!
Doncaster-born Oscar grew up dividing his time between his dad's home in Bessacarr and his Mexborough-born mum’s house in Newark.
And when he was in Doncaster, he spent a chunk of his Saturdays taking part in stage schools at Hall Cross School, which led to him performing at the small venue on King Street in the town centre.
Oscar’s first professional role was in Bertolt Brecht’s ‘The Spy’ at the Doncaster Little Theatre at the age of ten.
He said: “I used to love the amateur acting I did in Doncaster, and that led me to go to Mount View Theatre School.
“I got a job in a show called The Toxic Avenger, a super hero based on comic books that did well, and then I did a few stints in the West End. I went to do Nativity – The Musical, with Danny Dyer and Jo Brand, and they were great to work with.
“Then in 2018 I went to some workshops developing Only Fools and Horses – The Musical for the stage, with Paul Whitehouse. It was all very secret that they were looking at putting it on. We were told we were coming to audition for a production based on a series from the 80s and 90s based in South London. I guessed what it was likely to be, and took in some Chas and Dave songs. It turned out that Chas Hodges was involved, but he died just before the show opened, so it’s a bit of a homage to him.
“But I was there for all the edits and cuts, and the director offered me a part. There are so many iconic characters in it. Paul Whitehouse plays grandad, and Tom Bennett plays Del Boy. I play eight different characters, who were not in the television series so the pressure is off for me!
“We’ve been doing it since February.
“It is great working with Paul Whitehouse – he is a legend, but he also the kindest man. We are saying his words, as he wrote it with Jim Sullivan, but he’s not precious about it.”
Now Oscar, aged 26, has been nominated for a stage award for his roles in the show, running at The Theatre Royal, Haymarket. He is up against people including Jason Donovan.
He has been nominated for Best Supporting Actor in a Musical (What’s On Stage Awards) for his roles in the show. It is voted for by the public, and you can vote for Oscar by logging onto https://www.whatsonstage.com/london-theatre/news/20th-annual-whatsonstage-awards-nominees_50480.html.
Nominations and eventual winners are selected by a public vote.
Voting closes on January 27 2020.
Oscar is not the first to have learned their craft in Doncaster to be nominated for the award. Previously known as the Theatregoers' Choice Award, Sheridan Smith won the Best Actress in a Musical award in 2011 for Legally Blonde.
Ms Smith cut her stage teeth with the Doncaster Thespians Operatic Society, and took some of her first steps onto the stage as Annie in a Doncaster drama group production at Doncaster Civic Theatre in 1995.