I have taken the backup and loaded it onto my development server and the maintenance corrected the issue. It seems it may be a hosting issue (Bluehosts I believe).
I have also loaded up a prior backup that was done before updates on the 16th March. All the updates go through except for the template update (1.2 to 1.3), it has the common issue of failing to connect with a 403 error.
While I can install the template manually doing so causes the PB to lose the correct addon titles, like the language file is missing or in the wrong place.
The client has spent a couple of months doing extensive SEO and it seems that unless this issue can be corrected he will have to revert back to the site prior to the issue.
Please advise ASAP.