Flash 30 installer runs, but Flash 29 still installed (Win 7 SP1, Firefox 61.0.2)

I've followed the instructions on Installation problems | Flash Player | Windows 7 and earlier

This includes downloading the installer, install_flash_player.exe for Firefox (20 MB size) and running it directly.

Everything seems to work, but the installation page says I still have 29. Firefox lets it run--I see the tree and tire swing.

But for some reason the upgrade isn't "taking."