New PC - problems reinstating NOF 13

Hi there

On behalf of a client who has recently lost had to replace his PC...I am trying to get hold of a copy of NOF 13. I have a valid serial number, but can't access the download anymore as it is no longer available.

I do have a 10 install CD and a valid serial number for that, but the 13 upgrade was completed via a download purchased from NetObjects.

I have emailed support, both raising a ticket and independently, but no response as of yet.
Any clues please?
Thanks all!