Hello Daniel

Did you try the CG Museum in Seattle?
The address is
Coast Guard Museum Northwest
1519 Alaskan Way S
Seattle, Washington
98134
The phone number is
1-206-217-6993

Their hours of operation are
Mondays-Wednesdays-Fridays 9am-3pm

Please keep in mind the Museum is staffed by volunteers (who are usually very helpfull).
They have a pretty good selection of Coast Guard ship and boat plans, the cost of these plans I think are fair.
I don't have their email address to send along to you.
Please let me know how you made out.
Good Luck!

Mike