Can you install or downgrade to an older point release of macOS? I need to do some software testing against macOS. I know I can download the El Capitan and Sierra installers, but they seem to install the last version (i.e. 10.12.6) rather than the 10.12.0 release. 

Is there a way to get ahold of the older installers, or some way to downgrade?
There is no way to downgrade to or download an older point release of macOS from any official source.