Good question. Not sure if they have something new, but I thought Bill's son had put something out recently.
You can certainly still find some originals now and then online for a price.
Maybe Andrew (member BajaBronco here) knows. You can search for his username here on the forum (the advanced search tab will work for this) and private message him to see if he's got any current info.
Or e-mail him through his site at bajabroncos.com
Maybe someone here's got one too, so it's another good reason you asked.
Good luck. And let us know if you find one.
Paul