I've been using a lot of references to Celtic/Germanic/Norse pantheons in my story and I'm comfortable with that because I figure the Gods are public domain. I've also been using a lot of archaeological references such as existence of burial mounds, the Amber Roads, etc. Some passages have been written in proto-Celtic (footnoted for readers who want to know what it says in English) and runes are included also. BUT--I want to make a specific reference to the Gundstrap Cauldron. Much of the imagery on it's panels fits well with my story. There is a lot of debate over the use and sources of the Gundstrap Cauldron and about the only thing scholars agree on is that it must have been a ceremonial object that may have been taken as plunder by viking raiders (possible down the Rhine) before eventually being lost in a Danish bog. The character I would like to claim made the cauldron is a silver-smith of Celtic origin, but left the Swiss-Bavarian basin and traveled down the Danube which would have brought him into contact with the Thracians and sheet sliver techniques. Much of his working life was spent in Olbia, on the Black Sea. I'm in my second book, and he has returned to his homeland, where I'd like to claim that the cauldron was made as a ceremonial object for a Druidess. Can you cannibalize actual archaeological artifacts and write them into a story? How does this sit with other authors and publishers?