The 1837 Capped Bust Half Dime was the last year of the type. Later in the year, the new Seated Liberty design was introduced, not only on the Half Dimes, but on the Dimes as well -- then in 1838 on the Quarter Dollars, in 1839 on the Half Dollars, and finally in 1840 on the Silver Dollars (but never on any gold coins).
The entire mintage of 1837 Half Dimes is comprised on Small 5C and Large 5C varieties. Based on the PCGS Population Report data, the Small 5C variety is more than three times as rare as the Large 5C variety. In Mint State, the Small 5C that have been certified by PCGS are fairly evenly distributed among MS62, MS63, MS64, with only one less and no finer examples. This contrasts significantly with the Large 5C, where there are many more Uncirculated examples, inlcuding a number at the MS65 and MS66 levels.
The strike and overall appearance of the Small 5C and Large 5C varieties are nearly identical.