I have a 2-1960 shipped M19-0 that letters with checkered Goncalo Alves target stocks. I also have a 6-1961 shipped M53-0 that was shipped with checkered walnut target stocks. Both are diamond centers. No serial numbers on either. Sometimes the factory letters are dead on, and sometimes not. I have a early 8 3'8" M48 4 screw with three T's. It lettered as a 6" K-38. That is not possible. A recheck with Mr. Jinks proved it to be a factory ledger error. Don't believe all you read. Big Larry