My purpose is a book, that won't likely make a profit (certainly not if I charged myself an hourly rate for time spent). I hope to recoup my investment over time. I can't say it isn't commercial if I'm selling it, can I? So I'd have to call it a (bad) commercial project. I didn't set out to make money from this, my intent was to try and heighten awareness of the genre, pay tribute to the pioneers and raise my own profile a bit, in the process.
I checked Hoot's link thoroughly and lots of great photos there but no Jesse Fuller (or any other OMBs - closest I saw were Doc Watson and John Lee Hooker - both too on the periphery to pay for photos). Thanks though, I appreciate every lead.