That's an Old Soldier Sahib!
I've got one the same from the same year that had an FTR in '32 IIRC.
The "Z" on the Nock's Form is probably a sentencing mark; I forget whether it's "BLR" or "BER": "Beyond Local Repair/Beyond Economic Repair". In other words, repair or disposal.
(The use of "economic" might throw some of us North Americans: "economical" is more our usage.)
Edit: I see that had already been mentioned by Alan d'Enfield.