My NOS Brooks B5N from, I believe, 1978, also has a plastic badge, with the goofy-looking (IMO) lettering like that shown in the photos at the beginning of this thread. I would be happy to swap badges for a newer metal one that's better-looking, but they don't have the same rivet spacing. Old is 2-1/16", new is 1-7/8".

Now that badge that ollo_ollo posted is the real deal!