Pictures would definitely help here.
Mine wears a heart on the right where the Magnaflux symbol would be, and a cross and what looks like a teapot, besides the assembler, and date codes.
Mine sports a C and D. Which means April, but could be 1957,1983, or 2009.
It can get confusing.
Mine is an ‘83. It is visibly older than 12 years, but It doesn’t have enough wear to be a Greaser. I know it was owned by my employer for some time. I suspect he bought it for his boy, who is ten years my senior. That would make him 13 in 1983. A good age for a new squirrel rifle.
So 39 years old, the same as my little sister.
How old in approximate years is it? They were made for quite some time. That could narrow it down.
^The date code table is on this same page at this website.^
I like mine a lot. It sits next to its big sisters, the 760s in the safe, but goes out so much more.