Can you identify the model of this faucet?
You say you need "o-rings" but not specifically what part is the issue. If you take the part(s) to a good plumbing shop (a "good plumbing shop" is specifically a different thing from a big-box retailer) I would bet they can find what you need. The model number will be of little to no assistance to them, they know the parts by sight. 

American Standard has manufactured literally hundreds of different faucets over the recent years, and regardless of the model number many of the parts are common.

The closest in American Standard's current catalog looks like this: