Continental Arms did import Centaures, which were made by Fabriques d'Armes Unies de Liege. I've owned 2 or 3 of them, and as far as I can remember, they were all marked "Centaure". So it's possible Continental imported Belgian doubles that were not Centaures, and what you have may be one of those.
Comparing your gun to a Centaure, the least expensive model sold for $168 back in 1963. That's almost exactly what a Beretta Silver Hawk side by side sold for at the same time, and you won't buy one of those for $600 today. Going by the source I have, the Centaures with full coverage scroll engraving are the higher grade guns, so that may well bump yours up even more. Automatic ejectors would be another indicator of a higher grade gun.
Assuming it's from the same era as the Centaures even if it's not one, that would make it a 60's gun.
