The DVD ISOs are available on my local mirror, so they should be
elsewhere, too.
Where is your "local mirror"?
As I said, I couldn't see them on any of the mirrors offered to me.
The kernel.org mirror system has servers in the EU and has the DVDs.
>From the link below choose your architecture, download and verify the
iso files, and you should be good to go. http://mirrors.eu.kernel.org/centos/5/isos/