No way of telling without knowing what country and the condition.
These are still very common - worth no more than 2 cents.
i believe the value of a one cent stamp is worth 2 cents if used as postage but i have done research and believe yo can sell it for about 5 cents or so.
The half cent stamp available in 1942 would have been the orange Benjamin Franklin. Scott number is 803. It has a minimum value of 20 cents used or mint, so it probably wouldn't be worth trying to sell.
Martha Washington has only been pictured on four cent or eight cent stamps. They would be Scott numbers 636, 556 and 306. Consult a postage stamp catalog, they all have some nice value in mint condition.
No such coin exists. The US stopped minting half cents in the mid 1800s.
This is part of the Washington bicentennial issue of 1932. A dealer would charge 10 to 25 cents for it , mint or used.
1948-1963
1/2 a cent!
The last US half cents were dated 1857.
Roughly a cent and half. Depending on exchange rates.
It is not worth anything
A '60 Franklin half is worth about $11-12.