Jump on it!

[Scott Wilson]

https://pre98.com/shop/thur-april-30-ultra-rare-vietnam-era-usaf-experimental-k-1200-high-standard-trench-shotgun-mint/

[scosgt]

Is there documentation with it?
There is a local guy who stamps stuff in the same way.

[lyman]

you could post a question to John Stimson,

I think he has closed his forum down, but still answers emails from what I hear

https://www.histandard.info/