Considering its fame and (literally) iconic status, it's absolutely incredible that there is, in English, no good, general book about the Gundestrup Cauldron.
Absolutely incredible.
Oh, there are scads of specialist articles, and a few of general interest. There's one academic monograph that attempts to read the Gundestrup Cauldron as an early redaction of the same Keltic tale told in the Táin Bó Cualigne. (Since the scenes depicted on the Cauldron differ from the Irish Táin in several notable ways, the author contends that it represents an earlier form of the tale instead. Mmm: sounds circular to me.)
So I figure, I'll write it. Beautiful plates, and everything we know—or can guess—so far. The finding, general trends of interpretation, how it fits into its time, etc. There will, of course, be a chapter on its (massive) impact on contemporary paganism, as well as one on the solid gold Gundestrup-style cauldron (but with original art) that the Nazis commissioned (I kid you not). (It was discovered by divers in the waters of a Bavarian lake in 2001.) Honestly, you couldn't make these things up.
Well, I'll need a travel budget, of course—Denmark and Bavaria at the very least—and naturally I'll have to talk to the experts. Six months to research, six months to write. I figure I could probably do it for under 40 grand. In the book industry, that's nothing.
They say that as a writer, it's your job to write the book that you'd like to read.
So, I'm putting it out there. We really do need a good, accessible book about the Mother of all Cauldrons. There's a gap on the bookshelves here, folks, just waiting to be filled.
Feel free to make me an offer.