Restore Classic from iTunes fails - page doesn't exist

I've been trying to update my 8-Gb classic which has been fine for years. I eventually got a Duplicate Name error, which I have found here but with no resolution.

Anyway as I couldn't now see any music on the iPod I decided to Restore iPod from within iTunes (12.13.2.3). I have to clear it first as it is still showing as nearly full.

First I tried resetting the iPod from it's menus but that just seems to reset the iPod menus.

Next from with iTunes I tried Retore iPod, which should set it back to factory settings. I get an error The network connection could not be established". This is on a hardwired PC.

If I press More Info it takes me to an Apple webpage which says "The page you’re looking for can’t be found". This presumably the page with the iPod software.

Any ideas please?

PS I have also done the Windows ChkDsk which found errors and fixed them.