The original coronet head half cents from 1840-1849 were struck only in proof from a large berry reverse. Their rarity led to their being restruck from the 1850s to mid 1870s using 2 different small berries reverses.
The first restrikes used the reverse of 1856 with broken wreath under the "NT" of "Cent" and with doubling in those same letters. Examples are known for every date from 1840-1849 and 1852.
The second restrikes used a reverse with die file marks over "RICA" of "America". These are known for every date as above except for 1849.
In addition to these, some dates are known restruck from the regular large berry reverse, the most famous of which is the 1852 for which no originals are confirmed.
Mint Director Henry Linderman's personal collection had 2 restrikes of each date.
Photos used show a first restrike on top and a second restrike underneath and are courtesy of Ron Guth.