Artillery model shoulder stock
 

Can someone send me the link to the BATF letter that allows for firing my artillery model with shoulder stock attached. I thought it was on this forum.

thank you in advance

Here is a copy that I got from the BATFE web site a few years ago. The addressee has been redacted but it is the official response to the request to remove the restriction on some stocked Lugers with original or "close approximate reproduction" stocks. I don't know if the letter is still on the web site, I haven't looked in a long time.
Ron

thank you, Ron!

Would this also apply to the C-96 Broomhandle Mauser pistol too?

That letter addresses reproduction stocks for Lugers and Browning HP.
No mention of Mauser.
Other letters and documents exist regarding use of shoulder stocks.

You can find most of these on the ATF website.