Your Model 64-6 was in production from 1998 to 2002. CET2222 was probably shipped between October 2000 and July 2001.

Your Model 67-1 was in production, generally, from 1971 to 1988. If the barrel was pinned, that narrows it down more; pinned means 1977-1982, pin deleted means 1982-1988. More specifically, AJT0064 was probably made between July and Nov. 1985.

Yes, you can safely use Plus-P ammunition in both guns without worry.

What do you want to know about them? The Model 64 is the stainless steel version of the Model 10 Military & Police, which is chrome moly steel finished in blue or Nickel.

The Model 67 is the stainless steel version of the Model 15 Combat Masterpiece, which also has a blue or nickel finish.

Both guns were very widely used in U.S. law enforcement before semiautos took over in the middle 1980's. They are excellent handguns for many purposes.