All Australian Pennies from 1938 to 1964 had the initials KG just above the tail of the kangaroo.
It is not a mintmark, it is the initials of the designer of the reverse side of the coin, George Kruger Gray.
2002 mint sets in original package have a value of $15.00 to $20.00. The penny has never had a P mint mark.
The mint mark does not determine the value of a coin. If you have a penny and want to know what it is worth, please submit a new question and include the date on your penny as well as the mint mark.
A 1914 penny with no mint mark is worth about $1.50.
The Australian 1943 Penny was minted variously at the Melbourne Mint (no mintmark), Perth Mint (mintmark is a dot after the Y in PENNY "Y.") and Bombay Mint (mintmark is an "I" under King George's bust).
So very many were made is just a penny
A 1943 steel penny with no mintmark can be worth $.35 - $1.50
Value will vary depending on condition and mint mark. About $0.35
The lack of a mint mark means it was struck in Philadelphia, and value is 1 cent.
The majority of Australian Pennies with no Mint Mark were minted at the Melbourne Mint. The Sydney Mint was closed in 1926. All other Australian Pennies will have one of a variety of Mint Marks on them indicating that they were either minted at the Perth Mint, or a variety of foreign Mints.
Regardless of which mint mark it has, values are 5 to 10 cents. Uncirculated coins are a dollar or less.
8 to 20 cents depending on condition.
It is worth face value.