I have the mechanism for a Digitronics P135-20 Paper Tape Punch.
It turns out that Surplus Sales currently has one of these for sale; see
item "(EQP) P135-20/35".
It is accompanied by a three-page snippet of a much longer manual for this
punch.
See:
https://www.surplussales.com/equipment/pdf/eqp-p135-20-35.pdf
That's the only documentation that I've been able to find :-{.
I'd very much like to find/acquire the remainder of this manual, or other
relevant documentation. Can anyone help me?
Thank you,
paul