A couple of questions that I can't find the answers to: 1- What does the letter Z signify? 2- How come there is only 1 plate number?
The OP’s note has a plate position letter, “B” and plate number “B8006” on the front/face and plate number “6362” on the back. The prefix and suffix letters are the progression through the alphabet. The series 1935F $1 SCs had over a billion printed. The prefix letters A - L, used on todays Federal Reserve Notes specify Federal Reserve Districts. The OP’s note is a Silver Certificate, and Silver Certificates do not use districts.