Following the forums useful advice I re-visited the jeweler in question who assures me that there is actual proof that this version of a Montreal in an Autavia case did exist. I await copy of a magazine artical however has anybody else heard of such a version. Its beginning to worry me slightly.
The watch has Viceroy hands and black Montreal main dial (including the name / logo)with white (yellow markers) Montreal sub dials.

Any further advice would be greatly appreciated, sorry I'am unable to get a photo onto the site at this time.

Mark