G'day Barry,
I see Bob has answered your questions. Just an extra note: The Darling Pea is also known as Poison Pea in Queensland. It affects the vision of animals & they often die.

Hocussed shanty grog probably refers to home brew served by the publican poisoning the customers.

The Lachlan Valley is the area where I was born and is mentioned in many Aussie songs e.g. Lachlan Tigers, Streets of Forbes etc.

Cheers,
Alan