I downloaded and installed Oqueue yesterday, and it installs as version 1.6.0

The addon in game says I need to update to version 1.9.5, but the version I download directly from this site is 1.6.0

you either use the wrong site to download from or you probably have multiple WoW installs: you install oQ 1.9.5 into one folder but your game is actually running from another folder which has an older version of oQueue laying around.. check where the desktop icon's launcher properties says it's running from..