It is. As previously mentioned I did a quick install of workbench off the floppies and it booted just fine.
The archive was downloaded into winuae and un-lha'd there. I used nero to put it on cd and copied it off there onto the a4k. All long filenames are present and correct, and individual files appear to have copied over intact - I can read text files and programs run ok.
It just does not want to boot into the initial installation script.