I now have installed it successfully. Some was trial and error, so I am not sure of all the parameters.
The db is on MariaDB 5
PHP is 5.6
I am yet to set up a relay server for mail successfully, so at the moment users have to be set up without them requiring a validating email.
Setting up features is slow, but general navigation is acceptable. I guess a more powerful NAS would be better as the upload speed to my ISP would not seem to be the bottleneck.