The thing is, there were many new ships for SH3 long ago, but since GWX/NYGM/WAC reached a solid status and included most/all of them plus new ones, pretty nobody has been doing new stuff for the stock game.
However, you can try a seach in the "List of Mods" for the old threads where new ships were released and see if the links are still alive. If they aren't you can then ask for someone to send you a specific ship, I'm sure someone will do it
