Boring legal question

Hey everybody.  We are setting up a merch store, and of course I want to do some good Johnson jokes, among other things.  Johnson motors is out of business, but I think the copyrights are still held by other companies (Evinrude and Bombardier.)  Anybody know how that kind of thing works when it comes to selling T-shirts, mugs, stickers, etc?  If we take an old Johnson ad, modify it, and print it onto T-shirts are we going to regret that?  

Sorry for the boring post!