Hi Captfred -
There is a photo of me in there - but it is from my last computer & was not my last user icon / photo. Perhaps though, if I do a time machine restore of that folder to a few weeks back, it will have the correct image.
I'm still certain that the photo must be somewhere on my mac, because I did not delete it (someone bumped me while I was working in sys. pref. & I tapped a different icon) - at this point it has just become a point of curiosity!
Thank you for taking the time to help & keep me posted if you learn of anything else. I'll be sure to post anything I find here as well.
All the best,
Rax