Dr alexander leeper by john longstaff (1861-1941) - winner of 1928 archibald prize. Object Type: painting. Genre: portrait. Date: 1928. Dimensions: height: 115 cm (45.2 in); width: 93 cm (36.6 in). Medium: oil on canvas. Depicted People: Alexander Leeper. Collection: Art Gallery of New South Wales. John Longstaff Leeper1928