This is possibly William Johnstone, born on 9 Feb 1864, the eldest of six children of William Johnstone (c.1841-1909), blacksmith, and Margaret McDonald (1839-1929) who married in Launceston on 18 Apr 1863. The family lived at St Leonards. William would have been 27 years old at the time of the Tasmanian Exhibition in 1891-92.
He had a younger brother Walter John, born on 6 Oct 1868, who would have been 23 at the time of the Exhibition. When his mother died in 1929 Walter John inherited the blacksmith's shop and carpenter's shop at St Leonards that had been established by his father.