Thanks Rich
Yes, file.tcz certainly exists, and I can see it if I use a browser on another machine to look at the repo.
As this is is piCore I don't have a graphical desktop so no AppBrowser available, instead I am using tce-load.
But tce-load is giving me a 404 when it tries to download this extension, or any other (same issue with "visudo" which I could certainly do with...)
I suspect I have not set the tce-load environment properly (equivalent to the mirror setup with AppBrowser) but I can't find any documentation on it?
Cheers
Richard