Good write up, the Afghan government also had Gurkha knives made for the military, even though there are no Gurkhas in Afghanistan. I think all these were some what of test weapons to see what worked better.
I just wanted to correct some of the terminology used by the OP.
It is not called mashin khana, but rather Kaar Khaana, Kaar Khaana e Jangalak is the complete name located in Kabul.
The local name for the so called Khyber knife is saylaawa, there are no words in Farsi or Pashto as salwar, yataghan or dussak, they are Turkish or whatever words. Thus never used in country to describe what is so wrongly called a Khyber knife. So just to clarify the locals have a name for it and is called Saylaawa سیلاوه .
And as mentioned is some other posts, there never was a mazar e sharif arsenal, and the stamp represents mehrab and munbar.
Useful info otherwise, good job putting it all together
