A bomb -

You're very close.

The company the eventually became Holden was established in 1856.

In 1923 they signed a deal with GM to produce bodies for GM mechanicals.

Unfortunately they spent a bunch on expanding just before the depression and ended up deep in debt. In 1931 GM purchased the company for 1,111,600 Australian Pounds.

First all Australian vehicle was produced in 1948.

Some trivia for you all...