There's not a huge demand for older versions, but we do provide access through our beta group. Sorry I didn't realize you had a deadline! I went to the salesforce page to try and follow along to see where it might break in newer versions of Unity/Playmaker but it's a pretty hefty tutorial. LinkerWizard is not part of the standard install, so I was trying to see if it was required - did it tell you to install it?
Generally, add-ons and ecosystem scripts are updated to work with the latest version of PlayMaker. Getting older versions compatible with specific older versions of PlayMaker would be quite difficult! If LinkerWizard is the only issue you can do what that tool does manually (search for LinkerWizard on the forums).
If you still need access to an older version PM me about beta group access.