20c Pieces

Looks like a planchet flaw on one and a heap of Cuds on the other coins

Not really, more of a curiosity. Yours appears to be a 1971 20c coin.

I have quite a few 20c ones, but 50c, 10c and 5c are a bit scarcer in my experience.

Also, most of them are really unique, the same flaw is rarely seen in the same place on the same denomination coin, as it's a flaw in the manufacture of the planchet.

I'd estimate $1 - $2 per coin for 20c examples. Maybe $1 - $2 more for 50c, 10c or 5c.

$1 and $2 examples are fairly common, might be worth 2-3 time face value each.

They are sometimes called lamination peels / flaws and some can be very drastic, in which case the value goes up.

Yep she is the Australian Queen of the broken die