I'm looking for additional information on a John and Sarah Blanch, who moved to Australia in the late 1830s before John was killed in an explosion in 1839 in Melbourne, Australia. John's father, also John, was a well-known gunmaker in England and the business continued on for decades under the name of Blanch and Sons.

Also seeking a Bill Blanch, UK, purported to be a descendant of the above John and Sarah.

Many thanks.