Can't really date without a photo.
They had a huge product line; the label on the bottle would tell most of the story. You might browse completed ebay auctions for "parke davis bottle" (requires an ebay account and logging in) - I found 95 bottles, many of which had labels.
Then there is the parke davis catalog. A research project? Yes. There is no simple answer here.
And try out a new web browser some time...takes a few minutes to install and you might actually like it better :-)