Australian immigrant from Norway

My GGGrandfather "Charles Brown" arrived in Australia 1854 (and lived and died in NSW) on "Jacob Robinson" according to naturalization certificate issued 1869. I have all his family line to me, marriage certs, death certs. I think perhaps his name was not Charles Brown or had a Norwegian spelling. Have no idea where in Norway he came or through any other country on the way. Birth date 1821. Can anyone help with this.