1910 Peter sent word to Tony in America and to his parents in Italy that his business in Sydney, though still small, had made significant progress. Not least of its successes was a commission to create a mosaic floor for the Irish Chapel in St Mary’s Cathedral. When Peter first heard the cathedral was planning a mosaic, he approached Cardinal Moran, who explained that he already had a quote from a European firm, but the young artist would not take no for an answer. Poring over a copy of the Book of Kells by gaslight, Peter completed his design, based on ancient Celtic iconography, in less than a week. He prepared a quote for the job, which he later learned had undercut the European firm by half, and won his first major commission. For much of 1909 and 1910, Peter woke early each morning to refine and execute his designs, finally lugging the finished slabs of marble and terrazzo mosaic across town to the cathedral by wheelbarrow and by tram.

Later that year, Tony and Galliano Melocco arrived in Sydney. Tony immediately set to work helping his brother complete the Irish Chapel commission and Galli was sent, as a weekly boarder, to school at Knox College, across the harbour at North Sydney.