In that case, IMHO, you should just delete them from the GSL totally.
I don't think ships should be put in the GSL Layer for three major reasons.
1. You can't sink them.
2. For missions/campaigns they're often a problem when it comes to the AI's. They end up attacking the wrong ship(s) when left to select their own targets (Attack Current Point). They just end up in the way too often when doing historical recreations too.
3. Ships Move, often.
I think the same thing about aircraft, vehicles, creates, oil barrels and any other objects that gets moved around a lot. I think the place for them is in mission files and Layouts for missions that can be changed with ease, not the GSL Layer. For me, the GSL Layer is too stagnate for objects that were always on the go.
In the end it's a personal choice. I rip all of that stuff out before I even install a new GSL GOB. The list I started will provide you with a few of what's out there. They're my personal choice for high FPS shipping.
SS Adventure was put out by ChrisN. It's a conversion of Phil Crowther's FS2004 ship.
Looking for Lapwing's author now.....