Hello, I have a 1955 Model 12. I recently noticed that on this gun there is a small rectangular block of steel between the base of the barrel and the base of the magazine that the bolt shuts against. Picture a figure eight with this block being horizontal across the middle of the figure eight. Anyway, the right half of this block is missing. The gun fires fine, locks shut fine, but this still concerns me. Is this something a competent Gunsmith could repair with a weld or would something like JB Liquid Weld work? Anyone with any experience concerning this here?