Sharp had a long history with Sydney's iconic Luna Park. While living in London in 1973, he received an invitation to redesign the amusement park’s  face, and became one of Luna Park’s resident artists for much of the 1970s. When seven lives were lost in a fire in the ghost train in 1979, Sharp developed complex theories about the cause and significance of this disaster that haunted him for the rest of his life.

"I visited the Speakeasy Club in London one evening (1967). I saw a girl I knew, Charlotte, who was sitting at a table with two young men who didn't know. Being alone I asked if I could join them and I was made welcome … I gathered that the young men were musicians and as I had just written a poem which I thought would make a good song, I mentioned this fact, and one of the musicians replied that he had just written some music. In grand show business tradition I wrote the lyrics on a paper serviette and gave them to him with my address … I was pleasantly surprised when the musician, who turned out to be Eric Clapton, arrived at the studio with a 45 r.p.m. record with "Strange Brew" on the A-side and my song, "Tales of Brave Ulysses" on the B-side.

Soon after I moved to a nearby studio in "The Pheasantry", Kings Road, Chelsea, and needing someone to share with I asked my new friend if he would care to share the space and experience. Chelsea was an exciting place to live and Eric agreed …Eric asked me to design the cover for "Disraeli Gears". I loved record cover art and was very happy to do it … I was using fluorescent paints at the time. It was the height of psychedelia.

Some of the ingredients in the cover are made up from Victorian decorative engravings. It was done in black and white first and then painted with fluorescent colors. I tried to capture the warm joyful liveliness of Cream's songs. I later went on to design the cover for "Wheels Of Fire" for Cream.”

Martin Sharp quoted on http://www.milesago.com/People/martin-sharp.htm

A recurring element in Sharp’s work was the  "Eternity" signature. The inspiration for this was the story of Sydney man Arthur Stace, also known as "Mr Eternity". Stace was an illiterate former soldier, criminal and alcoholic who became a convert to Christianity in the late 1940s. From his conversion until his death in the 1960s, Stace walked the streets of Sydney at night writing in chalk the single word "Eternity" on walls and footpaths. Stace's identity remained unknown until he was revealed as the writer in a newspaper article in the early 1960s.