Nev

Unfortunately I no longer have a working copy of WX5 V8, but I am pretty sure there is no upgrade path from V8 to V13 unless you have V9 as an interim step.

You should be able to recreate your site by starting a new project in V13 and then copying and pasting either between the open V8 & V13, or by copying and pasting from the existing website. 

If you wish to recreate your template, either save your website to disk in V8 and then retrieve the header, footer, background etc from the res directory, or you can use an ftp client like filezilla and retrieve the res directory contents directly from your domain.

Good luck and let us know if you need further assistance.