Counterstamps

I have a cartwheel with a counterstamp that looks like part of the design for the Montreal penny.

This is a "squeeze job" (follow this link). Someone simply squeezed the two coins together in a vise. Perhaps the reverse of your twopence has a "texture" caused by the patterns on the surface of the vise pad? Or else a hammer was used.

So, it is not an error but PMD (post-mint damage).

I've been watching this thread hoping someone would come up with the answer! Camerinvs I always learn so much from your posts.