The coordinates above won't take you to or near the cache,
but to this neon sign that looms over the Ballard skyline
It is however visible from the cache site (certain times of the year at least) located in one of Seattle's fine public parks.
Use this still present sign along with these
three vanished signs to navigate closer to the
cache location, at least to the nearest intersection :
Once you figure out the name of the Seattle Park that houses the cache, you are almost there.
Remove all consonants from the park name leaving only the vowels: a, b, c & d
Make a five digit number by stringing a,b,c & d together.
Add 19546 and 2386 to your five digit number to get the coords
15 digit checksum = 48