I have a catalogue featuring it.
Hi Jeff,
That looks like a nice watch.
According to the aution the Case Ref # is ST 166.090 ( ST means it's made of Stainless Steel & 166.090 is the "model" number ).
Here's a scan of the 1975 catalogue that I have featuring the watch.
( see righthand page, watch "b" )
So yours has a silver dial ( Omega sometimes offered the same watch with slightly different dials see watch "c" on the same page above ) & a bracelet ( it looks like the original ).
According to the auction it has a 1022 movement. I'm NOT an Omega movement secialist, but the 10xx range was used in a LOT of watches in the 70's. It has a very good reputation.
Precautions with your watch ? I'd try to keep it out of water. According to the little symbols in the description, it was originally sold as a water resistant model, but after 30 years, I'd get it checked before I went near water with it.
As for using it. Since it's an automatic, it is kept wound by the movement of your wrist. To start it, simply shake it a few times ( you can probably wind it via the crown if you want ). I'm not sure how the quickset for the date works.
Enjoy your watch.
Steve