Ann: Notice of Extraordinary General Meeting/Proxy Form, page-4

Assuming you hold the shares in your personal name then my understanding is as follows.................

Unfranked amount will be income and taxable at your usual marginal rate. So you will pay tax on the entire 57 cents
You will then pay tax on 50% of the capital gain given shares have been held for 12 months. In your case, the capital gain is the difference between 92 cents (cap return) and your purchase cost of 30 cents.

For some taxpayers, it will be better to sell on market so that their entire profit is a capital gain. This is an important decision and I suggest you speak to your accountant.