Hey Alan,
First take a look at the shield: Is it just a tree, or does it have "tree brand" underneath? If it does, and the handle material is delrin, your knife is from the mid 1960s. If it is just a tree, with no trademark symbol (r), your knife is pre 1976. If your tree has a trademark symbol, it was made after 1976.
Take a look at the tang stamp to help determine the age. If the tang stamp reads "Boker / USA", it was made sometime between 1945-1983. Take a look at this web page for some great info on dating Boker knives by the tang stamp
http://thehawkeco.com/knifesite/BokerNo ... notes.html. Hawke is an AAPK member!
I hope this helps. If you could post a pic, I'm sure we could tell you a little more.