Where can I find version info of the installed tools?

Open System Preferences > GPG Suite / GPGPreferences and select 'About':

gpgp_about.jpg

In case you want to report version info for a support case, open 'Send Report'. Enable the 'Attach debug log' option.

For existing discussions, make sure to include the URL of that discussion in the 'Additional info…' field. That way our support team can easily connect the incoming version info to your existing case.