No picture to determine if the front barrel has been shortened. If it has, it's beyond any reasonable restoration.
The XXI looks like a cross out of some other stock mark. That location is usually where the makers' mark is located.
Valuations are pretty much on point.
I have a bolt for it.
Just don’t like to store them assembled.
My dad had this rifle for decades and I have never shot it.
Took it to a local gunsmith who really seemed familiar with it as well as my 8 mm mauser.
He checked it all out and proclaimed it ready to shoot.
May run a few shells through it this weekend and see.