Hi, Noel,
I am, as you say, quite certain. Those pickups are copies of Gibson humbuckers and are not the same shape as Hofner "Diamonds" (which would be the units used on a 1963 Hofner). Hofner Diamonds were narrower than Gibson hb pickups.
Until the mid 1970s, no Hofner guitar had obvious copy components - that was a phenomenon which didn't come about until the later 1960s - and even then, it was an Asian innovation (apart from the odd hand-built replica here and there).
The Hofner company designed their own components and either made them in-house or had them produced on contract. Additionally, original 1960s German-made Hofner solids with clear and obvious Fender-style body shaping always had single-sided headstocks - until the recent batches of Chinese-made guitars, that is. I did give thought to buying a recent Colorama (they had them cheap at Peter Cook's), but passed when I saw the non-authentic three-per-side headstock, which I don't think suits that guitar.
Happily, Steve Russell's superb Hofner / Selmer / Watkins / Futurama / Bird website almost clears up the mystery:
http://www.vintagehofner.co.uk/vintagehofner/oddballs/odb12.htmlA prototype from 2003 or so (though I think your pictured example is a short-batch production model from later).
HTH,
JN
PS: There was this, in the late 1970s:
http://www.vintageguitar.com/online-readers-gallery/electric-guitars/hofner-164-iv-electric/But you will appreciate the obvious differences immediately. The 1970s were as unhappy a time for Hofner as they were for Fender (and for fans of both makers).