1938 to 1952 George VI Obverse/Reverse dies

Obverse 3:

IMP has small serifs and letters are widely spaced. Vertical stroke of P at IMP is aligned with a rim denticle.

Used on all pennies struck in Australia from 1938 to 1948.

The outer rim has 156 short denticles

Obverse 4:

The mint mark "I" is usually present below the bust and there are taller denticles. Serifs are more pronounced and the letters almost touch. Vertical stroke of P at IMP is aligned over the gap between rim denticles. The I mint mark only appears on obverse 4 but its absence is not 100% completely reliable because a few 1942 pennies were struck at the Bombay mint without it.

Used on pennies struck in Bombay, 1942 and 1943.

The outer rim has 145 taller denticles

Obverse 5:

This obverse had the IND:IMP. deleted from the legend and the F:D was expanded to FIDEI DEF.

It was used for all pennies minted from 1949 to 1952.

The outer rim has 155 rim denticles

Reverse D (Melbourne):

The upright legs of the P in PENNY and of the U in AUSTRALIA point at thick denticles while those of the L and I point at thin denticles.

This was used at Melbourne and Perth from 1938 to 1964. 

The outer rim has alternating thick and thin denticles, 81 of each. 

Reverse E (Bombay 42):

This is similar to reverse D but the rim denticles are much taller as shown in the image. Also, the kangaroo's appearance is different and the lettering is slightly bolder than the reverse D die.

The P and the Y of PENNY line up with the thicker rim denticles

and large dots are present before and after the P and Y in PENNY.

This one was used at the Bombay mint in 1942 and for a small number of the

1943 minting. 

The outer rim has thick and thin denticles, 77 of each.

Reverse F (Bombay 43):

Almost identical to reverse E but for the rim denticles which are much shorter, and look more like those of reverse D.

This was used at the Bombay mint for almost all of the 1943 issue.

The outer rim has alternating thick and thin denticles, 77 of each.

Reverse G:

This die is also very similar to reverse D. The differences are in the alignment of the P in PENNY which points to a thin denticle and the L and I in AUSTRALIA which points to the wide denticles.

This reverse was used at the Perth and London mints from 1951 to 1955.

The outer rim has alternating thick and thin denticles, 81 of each.