I misread the requirement for libc - all of our Kindles have a new enough libc to run that binary.
The KT and PW1 are both using the same ARMv6 based system chip and all of the newer models are using an ARMv7 based system chip. But the ARMv7 will run all ARMv6 code (ARM is very good at that).
So there is a good chance it will run on all touch screen models.
- - - - -
That mpack/munpack binary does not do s/mime -
But that was just an observation in my notes, leave it up to someone else to add s/mime support.
= = = =
No, I don't remember all of that just off the top of my head.
I have open in front of me a list of such facts I have been working on for the past several days.