NZ gs badges

[GTB]

I know very little about NZ badges so I am asking about the status of the attached two. The left-hand badge is fitted with copper loops, die-struck and with finely pebbled ground to the letters 'NZ', both front and back. The right-hand badge has a slider and underneath the fixing point is a reinforcing 'rod'. Moreover, the letters 'NZ'are perfectly smooth with no raised outline or pebbling and this does not look as if they are rubbed smooth because from the rear the lettering has no pebbling. Would the reinforcing and slider merit a sealed pattern and thus give a time frame?

GTB