I have worked on a lot of 21's,several hundred,never had one off face,plenty with a worn bolt. The adjustment is for bolt engagement and is a screw on the barrel notch for lock-up. If too much engagement,sticky bolt.Sounds like a gun for complete rebuild. i.e.,new stock, refinish metal,check parts. Consider the value of the barrels etc. and the rebuild and the total should come to $7500 max. So,with stock about $3750, metal work $2000. Then the piece should sell for $1750 max.