Dave,
Having been an "Instructor of OJT's" or in the more common vernacular an "Apprenticeship Instructor" who taught Marines with little or no gunsmithing skills how to build unmentionable NM Rifles, I have sincere empathy for what you are doing with Josh. Still, you are going far beyond the challenges I ever had to deal with and you have my greatest respect for doing it.
Please inform Josh I wish I had had more of my Marines who had the desire and drive to learn gunsmithing Josh has demonstrated, especially with what he has to overcome to learn it. Also, I had to sweat blood to learn hand filing and did not have to deal with the challenges he has overcome. So I have great respect for him as well.
What a truly splendid thing you both are both doing!!
Gus