I may be able to help. Thomas Pinder and Lavinia Maynard's second son was called William Thomas. He was born in England in about 1853, and came to Australia with his mother in 1854 (his father came a couple of years earlier). I am descended from his younger brother Thomas, who was born in Bendigo, where I was born too. There are still some Pinders in Bendigo, some in Geelong, and some in Broken Hill and Adelaide, I think.