Sorry, but that's not a CCS 25. It's a 20 ga (Miroku) shotgun fitted with rifled barrels. The CCS 25 has a forward sliding (not detachable) forend like the B25 shotgun from which it derives. I don't believe this one to be an original FN-Browning rifle but suspect an example of the many transformed 20 ga. shotguns. To verify, you could check the typical rifle action machining (not hollowed out bottom, gas screws, wall thickness, etc.) as I posted above.

Also, an original FN built double rifle comes with a authenticity certificate naming the engraver and craftsmen who built the gun. Here's mine, for instance :