I have a 1957A silver certificate dollar bill signed by C. Douglas Dillon I also have 3 1935 silver certificate dollar bills that are series E, F, & G. The E series I cannot read the name of the secretary of treasurery, but the bill is in great condition, just cannot tell what the letters are. The F series is Robert Anderson and the G series is Douglas Dillon. Are these bills worth anything or should I just hold onto them longer