Hi everyone,

I recently came across some Yale keys I've never seen before. I was hoping someone might know what they were used for:

RN-9 1/2 GMK, 4 pin length. Were these only for masterkeyed cabinet locks? I have a cabinet lock in GE section that is 4 pin, but only has 3 active pins, the 4th is a dead pin (no chamber in the bible, just in the plug).

RN-19 E1R, 3-pin keys. According to old catalogs these were used in some trunk locks?

3-pin keys that are the reverse of the typical Yale RN-13. I've never seen these before or anything that uses these.