Ok I got it now. I think I understand how it was fired.
I would still like to see a photo of ...is it notched out?"
Here you go. Both are numbered "422b".
"The matching barrel is unusual and a rarity for sure."
Note the barrel is plugged (welded)
"The butt plate is 1352, no italics lower case "a" or "b" stamped below or after, (with a four digit number due to spatial confines they sometimes dropped the letter completely or put it under the number)?"
Man you are good. As you can see, you can not tell with the dirty back plate. However it is marked with a "1352b" on the catch.
Why are the whole drilled in the feedblock. I think they are tapped. I would guess for some kind of belt guide? Also note the black paint on barrel.
Here is some of the damage. The bottom plate was ripped off and bent up. I will probably have to get a new one. The trunnion was cut in half and the back half was smashed. I do not know if I can get it back to where I can use it. The recoil plates are cut and welded for a complete lose other except for the dagger.
I sent you and email. Please do let me know if you can help me out with any parts. Thanks again for all your help!!!