All About Pocket Knives

Heres a neat little item, its a key chain with a bottle opener, screwdriver tip and cutting edge on the blade. Its of the Dupont era . The other side was to be used as advertising. This one says " Your Imprint Here in 1/16th block letters"
I'm guessing it was a sample.

How old do you think it is?

I have some of this pattern and I always thought they were 1960-70's but a couple I have found have advertising that was much older. I really do wonder when they first appeared.