Thanks, léonie. I have 3.4.5, but I'm pretty sure it's was an upgrade from a disk install beginning with 1.1. Somebody somewhere has the DMG, and they will eventually make it available.
I'm not in any distress– unless my 2011 computer dies in the next coupe of weeks. In fact, I'm getting close to being fully migrated to Lightroom. I just think I should have access to the application that I paid for as long as it's supported by the OS, and I shouldn't be punished when I buy a new computer or have a hardware failure.
I'll never buy Photos after the way the Aperture thing has been handled. In fact, I've dumped FCP and Motion and gone back to Premiere and After Effects.
Thanks again