My great grandfather was William Blackaby, his mother was Ann Wakeham and her parents were Richard & Ann Wakeham (nee) Andrews. This is where our facts differ. This Richard was born 1803 d1884 and his parents were Richard Wakeham and Elizabeth Skilton (not Horswell).
Do you know Ron Wilson from Melbourne? I met him about 2 years ago when he was in Tassie. He would be descended from the same Elizabeth as you are.
You can contact me offline if you wish - firstname.lastname@example.org