There is plenty of case law to refer to. I provided earlier a link to an old forum thread that addresses many of the legal issues that are indicated as being present here, complete with several applicable case cites. That said, each case will present its own set of facts that need to be personally reviewed and analyzed and that is what will ultimately determine whether a use is infringing or not.
I think both doodah and Taxing might have misunderstood what skullcreekdesigns intends to do with the barrel heads - there are several possible examples online of products using whiskey barrel heads - but, regardless of what is made and sold, if a trademark/logo is used and permission has been granted from the rights holder to use it, there is no problem from an IP standpoint.
skullcreekdesigns can certainly find an IP attorney in his area to get a personal review but that can be costly where permission from the rights holder could be cost free.