RE: New vs used steel trawler
A ten year old boat can be worth more than a newbuild if the older boat has features, construction, equipment, design, etc. that give it more value to the market. I don't know why US-build should automatically command any sort of premium except to people who are of the "only buy Made In USA products" philosophy. Most of the higher-end recreational boats these days are made in other countries, labor costs being a big factor in this.
If you have not realized this yet there is an active participant in this forum, Mark Pierce, who recently took delivery of new-build Seahorse Coot. He lives in the San Francisco Bay area. I'm sure he could provide you with as much detail about these boats and the ordering, manufacturing, and delivery processes as you could ever want.