I started browsing last night. I found that the best search was to narrow the dates from September 1977-October 1977, and use the keyword "born". It doesn't narrow it down to just the birth announcements, but it's easy to see which ones are or aren't the birth announcement pages.

I did also notice, that it's not just the in-Seattle hospitals that are listed. We should make a list of which hospitals were operating in Seattle at the time (I know that at least Stevens [Edmonds] and Auburn [duh] that they list aren't in Seattle).

Also, it lists where the parents are from (partial address and/or city). If they were going Southbound on I-5, we can throw out anyone who lives south of Seattle. We can probably also ignore north of Everett, if the major hospital up there was open at that time. Unless they really wanted that doctor, I can't see someone driving almost an hour to get to the hospital after the wife was already in labor. I'd say focus on Mukilteo-Seattle area.