What is the value of a 1935 K US 1 dollar silver certificate?

Please check your bill again and post a new, separate question. H is the highest series letter for 1935 $1 silver certificates.

In fact no US banknote series has extended to "K". The series letter, if any, will be next to or below the series date. It's not to be confused with the prefix or suffix letters on a bill's serial number or, in the case of a Federal Reserve Note, the district letter appearing in the center of the Federal Reserve seal on higher-denomination bills printed before 1990 as well as current $1 and $2 bills.