as a matter of fact, the tax rate for high incomes in 1960 was 91%. you can find verification at the following location--
audiences in 1960 would have found nothing amiss watching that episode because the scriptwriters actually portrayed the tax structure of the period. it is only recently that anyone would have thought a highly progressive tax structure was anything unusual.
as it stands, this episode is one of the better retelling of "the monkey's paw" trope in the history of television.