Thanks for that, Frances.
Ada Agnes Fasche (with an F not a T – Vic BDM transcribed it wrongly) was Thomas Karran Maltby's second wife and my great-grandmother. His first marriage was in 1857 to Mary Ellen Ryan who died in 1879. I can supply more details to anyone who's interested.
I understand Robert Maltby was a brother of Thomas Karran Maltby. According to a posting to this board on 22/1/2010, there is a memorial in Braddan New Burial Ground, Sect 1 Block 5 # 3234 which states that 'Robert James Maltby - - died on his passage to Australia on the 6th of August 1863 aged 22 years". I did not previously have the name of the ship.
I've had no luck tracing TK Maltby's migration from the Australian end, but was hoping some record might exist at the IOM end. I'll keep trying.