I downloaded the two zip files (c.zip and fr.zip) thanks to SmOgER, unzipped them on my PC then downloaded them onto my SD Card. It did not work
I then placed the actual zip files on the SD Card at: SD/Android/data/com.google.android.apps.translate/files/ol/v3r1/tmp\v3r1\zip then I Opened Translate, went into offline packages and selected French. It worked, it recognised the zip files (and did not try to download then again it just went straight into installation.
One complication maybe. The uncompressed c.zip creates a folder call c, under SD/Android/data/com.google.android.apps.translate/files/ol/v3r1. This is where the Profiles.txt file goes.
I suspect that if I had moved Translate itself from the SD Card onto the phone and installed the offline package from Google Play it too would have worked.