The only point I do not understand in your Jig is how the washer is fixed in the correct position and what prevents it from moving after each letter is stamped.
From
Stamping JIg Instructions Manual:
Once the washer is inserted, rotate the BitJig to the lock position, securing it firmly, note
that the washer holder inside the base moves down
I assume there's some thread inside to "clamp" the washer in place, but I can't envision how that works since the washer fits through the hole of the base that moves down.