Congrats Gary -
We just found my husband's birth mother (now deceased) and he now has 3 half-brothers. WARM is where I started 26 years ago and they were very helpful.
For any others looking for maternity homes, perhaps an email/letter to the Seattle Public Library might help provide info. In my husband's case he did a DNA test and came up with two cousins who were a 99% match.
PS Longtime friends (old farm family) of mine live in Thornton.)
Susan