Doc, you are correct, #67 was a typo on my part, the correct number is #69. I've edited my post to reflect this.
Folks, if you go to this link to read a PDF file issued by US Dept of State you will find the named concerns on page 3.
https://www.pmddtc.state.gov/complia...ufacturers.pdf
2. Registration Required – Manufacturing: In response to questions from persons engagedin the business of gunsmithing, DDTC has found in specific cases that ITAR registration isrequired because the following activities meet the ordinary, contemporary, commonmeaning of “manufacturing” and, therefore, constitute “manufacturing” for ITAR purposes:
c) The production of firearm parts (including,
but not limited to, barrels, stocks,cylinders, breech mechanisms, triggers, silencers, or suppressors);
Ken H>