EAW, Recknagel (ERA) and MAK all make mounts for Chapuis double rifles.

www.eaw.de
www.recknagel.de
www.mak.ag/catalog/

All of these are very good and fine made, but MAK offers the lowest mounting option with only 12mm build height. On a double rifle it wont be practical with any lower - as you need some space between the scope and opening lever in order to reload your rifle without to much effort.

So in my opinion claw mounts would look the nicest - but wont offer anything usefull regarding mount height, because there is a limit how low a scope can be mounted because of the opening lever.

I can post a picture of my mount later:-)