Also, don’t try to print without the rubber print hammer, the typeface
metal is softer than the metal of the print hammer, and without the rubber
hammer in place you will quickly flatten out the letters. A small piece of
vinyl tubing can work as a temporary substitute.
Frank
The people on the Greenkeys forum
<https://mailman.qth.net/mailman/listinfo/greenkeys> have remade the TTY
hammers.