‘to have death adders in one’s pocket’: meaning and origin

The Australian-English phrase to have death adders, or a snake, in one’s pocket, and its variants, are used to describe a person who is reluctant, or very slow, to pay for something.
—Cf. footnote and let the moths out of your purse.

The image is, of course, of a snake biting the person when they put their hand in their pocket to get at their money.

These are the earliest occurrences of the phrase that I have found, in chronological order:

1-: From the Daily Pictorial (Sydney, New South Wales) of Friday 14th November 1930:

Got 300 Guineas by False Pretences, But Nobody Cared!

Until somebody sells the breath of spring, yesterday’s effort by Mr. Walter Black, vice-president of City Tattersall’s Club, will be Australia’s record novelty auction sale.
He sold a hair from Phar Lap’s tail to members for 300 guineas.
“Come on! Come on!” he cried. “There are no death-adders in your pockets. Dip deeply for the honor of Tatt’s.
“Gents,” he pleaded. “This cash means votes for Mrs. James Clarke. Make her Queen of the Harbor.
“Think of it—a hair from Phar Lap’s tail! You cannot have the horse, but here’s a hair. A whole hair!”
“Hair! Hair!” cried members, and soon 300 guineas had been paid over.
The highest bidder got the sacred hair, and all other bids were confiscated.
And then——
“Well, gents, I cannot tell a lie,” said the auctioneer genius. “That hair is merely a hair from the dog that stung you.
“We plucked it from a crippled cab horse.”
And he escaped without a police guard!

2-: From the Evening News (Rockhampton, Queensland) of Thursday 8th July 1937:

TURNED DOWN TIME AND AGAIN. SAYS MAYOR
Aldermen To Act In His Place
ALD. JEFFRIES APPOINTED DEPUTY

Stating that he had been turned down time and again when he had asked aldermen to deputise for him at social functions, the Mayor (Mr R. W. Evans) last night asked the council to appoint a Deputy-Mayor to relieve him of some of his social duties, which were increasing rapidly.
After discussion on the question of a permanent appointment, Ald. J. Jeffries was voted to the position for a month.
[…]
Ald. Jeffries having previously been appointed to the position, Ald. T. A. Dunlop moved that he be appointed to act during the term of the council.
[…]
Ald. Jeffries: I am not keen on the position. You can’t go to these functions with a death adder in your pocket; your hand is in your pocket all the time. I am not keen if you don’t want me.
The motion was carried in amended form, that the appointment be for a month.

3-: From Don’t Write, the Enemy Peeps, published in Smith’s Weekly (Sydney, New South Wales) of Saturday 3rd May 1941:

You pilot her into the lounge and wait till the waiter slides up.
“Yessir?”
“Bring me a pint of the best.”
“Yessir. And the lady?”
“I think I’d like a double-header Hennessy’s with split soda and don’t forget the ruddy ice.”
“Yes, madam.”
When you get your breath back you say, “Hey, listen, Birds-nest. Do you think I’m a mint?”
“Don’t be a piker. You got death-adders in your pockets?”

4-: From This Australian Slang: A Few Oddities of Expression Which We Can Teach Our American Friends, by Edna Dimmock, published in The Argus (Melbourne, Victoria) of Saturday 18th April 1942:

How many of us know that “to dip south” means to search in one’s pocket for money? And that “to have death adders in your pocket” is to be mean with money? But worse still, when you are “fly-blown” you are penniless.

5-: From Truth (Brisbane, Queensland) of Sunday 11th April 1943:

£4,000,000 A DAY WANTED

Four million pounds a day will have to be subscribed by the people of Australia from now until April 20 if the £100,000,000 Third Liberty Loan is to succeed.
The loan is still lagging. The Treasurer (Mr. Chifley) revealed that only 90.000 people had contributed £60,000,000.
Where are the rest of Australia’s purse-men? Kill that death adder in your pocket!

6-: From an advertisement for The Ballarat Brewing Co. Ltd., published in The Argus (Melbourne, Victoria) of Thursday 8th November 1945:

“Have you got a snake in your pocket?” asked Bertie.
Recognising Bertie’s delicate hint to mean it was our turn, we produced a coin from a pocket and bought a glass of Ballarat for Bertie and for ourselves.

Note: It seems that the term death adder originally appeared as an alteration of, or error for, deaf adder, reflecting the actual or perceived deadliness of the snakes in question.