Ron Guth: 1834 Half Dollars are found in three major varieties:
Large Date, Large Letters
Large Date, Small Letters
Small Date, Small Letters
Collectors should have no difficulty discerning the size difference of the dates and the reverse letters once they familiarize themselve with the pictures offered above. None of the three varieties is scarce or rare, bvut the 834 Large Date, Small Letters is the least common.
As of September 2011, PCGS reports having certified more than 150 Mint State examples of the 1834 Small Date, Small Letters Half Dollar. MS-64 is the most plentiful grade, followed by MS-62, then MS-63. MS-65 and better examples are very rare, and the finest 1834 Small Date, Small Letters Half Dollar certified by PCGS is a single MS-67.