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).
There's never been an E mint mark on US coins. Please check again - if there's a mint mark under the date it will be either D or S.
1951 Wheat penny: With no mint mark, in very fine condition is worth $0.10, uncirculated is worth $1.50, proof is worth $35.00. With D mint mark, in very fine condition is worth $0.10, uncirculated is worth $0.60. With S mint mark, in very fine condition is worth $0.10, uncirculated is worth $2.00.
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.
The mint mark is below the date.
1956 Australian Pennies minted at the Melbourne Mint have no mintmark. 1956 Australian Pennies minted at the Perth Mint have a dot (.) after the Y in PENNY (PENNY.)
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 penny
KG is the initials of the designer of the reverse of many Australian predecimal coins - George Kruger Grey. The Perth Mint inserted a dot between the KG (K.G) on the 1940 and 1941 Australian Penny as a Mint Mark to indicate it was minted at the Perth Mint.
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 1922 Australian Penny has no mintmark. Actual mintages were Melbourne - 9,529,440 and Perth - 3,168,000. Identical dies were used so the issuing mint for a particular 1922 Penny cannot be determined.
Directly below the date. If there is no mint mark, then it's from Philadelphia.