Apologies if this is off-topic - please close away if it is.
I am currently engaged in writing a book. This isn't speculative - I have a commission and an advance and a budget to spend on securing additional things required such as images and photographs. And the subject matter isn't the sort of new-age nonsense academics get occasionally pestered with during their careers.
Although it's not an academic text, one of the chapters is quite academic in nature, and discusses some niche topics in archaeology. I'd really like to secure some photographs of the finds in question: they're easy to track down online.
This question - I'd like to use a figure from a paper; what's the best way to do this? - makes it clear that, as I suspected, I'd need permission (and like to pay a fee) to republish the photos. That's fine, and of course someone deserves remuneration for my profiting from their work.
The trouble I've got is that no-one I've contacted seems the least interested in helping. I've mailed several journal editors and contributors alike, asking for permission and offering to pay, but I've had no responses at all.
I was once a PhD student myself, and I'm aware that many academics are disinterested in such relatively trivial requests. But I don't know what else to do: if I can't secure at least a few photos, the whole book is likely to be cancelled. Who am I best off approaching about this, and how am I best off approaching them to try and generate some interest and engagement?