The Debian/Ubuntu update of Sparrow appears to work OK. As a new Linux user I just had to learn how to purge the old debian package install and replace it. I couldn't just install the new package from App Centre without getting rid of the old one first. It took me a while to figure it out. But all of my wallet db files were still intact and everything connected to Tor and private Electrum on the Start9 just fine. And the Windows version appears to be operating equally well. Thanks #sparrow