Sydney was very interested in the works of Charles Dickens, so much so that he later named his daughter, his house and his dog from names in Dickens novels. He used to perform monologue sketches in vaudeville and it is likely that he was doing this during his spare time whilst working for the Crown Derby china manufacturers. On 9 May 1905, he played the part of Barty Hayseed in a musical romance called Jan the Jester. It was performed by the Cauducean Club at the Kings Hall, Covent Garden. There is also a photograph of him in the part of the Dickens character Uriah Heep.

On 7 May 1908, Sydney played the part of Tom Oxley in the play Sunday, put on at Freemantle Hall in Eltham in aid of Bexley Lawn Tennis Club, as reported in the The Eltham and District Times.

A report in The Stage on 5 December 1912 mentions that Sydney performed a monologue at a concert for the Artists Benevolent Association at the Criterion Restaurant. On 10 January 1913, The Willesden Chronicle carried an advertisement for a recital in which Sydney and Vera would be participating at St.Matthew's Hall in Harlesden. Both The Willesden Chronicle and The Kilburn Times reported on the event which took place on Thursday 16 January 1913. On Tuesday 28 May 1914, Sydney was amongst others who participated in a Compimentary Benefit event for his grandfather, W Mortlake Mann. On 14 May 1914, the Hampstead and St Johns Wood Advertiser carried an advertisement for the event then, on 4 June 1914, published a report of the proceedings.

Sydney and his wife Vera used to take part in amateur theatrical productions at Brentham, Middlesex, for which some records exist. He was also earning some income my teaching elocution to actors and a book of hand-written extracts of Dickens works which he used remains in the possession of his family.

Sydney was out of work for some time after leaving films when the industry suddenly declined. He considered, at one stage, emigrating to Australia. The family were ready to go but they never did. Sydney's make-up box and a selection of wigs and hairpieces survive with other keepsakes in the possession of his family.

Sydney was the producer of at least two plays for the Old Masonic Dramatic Society. His recollection of the performance of Murder on the Second Floor was very amusing as reported in The Era on 17 June 1931. The following year, the production was Lillies of the Field and The Era of 17 February 1923 reported on the event.