In the end, I found it easier to toggle my hosted php version between 5.6 and 7.2 when I wanted to view the old moodle 2.9 site or build the new moodle 3.4 site.
I am sure there are better approaches but I found the learning curve for migrating from a hosted moodle to a Windows PC too steep, whereas toggling the hosted php version was straight forward.
Thanks for all the advice.