Just to give some people something to think about. Both the Astute Class Submarine Manual
and the Type 45 User Manual
contain shipbucket images, and the author, Jonathan Gates, was quite careful in obtaining permission from the artists.
Generally it's not hard to find us, and I think most wouldn't mind being published even if the only thing you get out of it is a mention in the book, and perhaps a copy of said book. I certainly think the above look cool on my bookshelf
If an author doesn't credit us, he's just being lazy, and you might want to wonder what else he's being lazy about.