Try this.
Got an 11mm rail on your combo gun, both mine do. I was having a tough time finding a set of low rings, tried Leupold Mediums and they were too high.
I found this little item a 11mm to Weaver adaptor that only adds about 1/8" to the hight of the scope and you can use low weaver style rings. I suggest rings that have a good stout clamp system though.
Both the guns I have in the "Show your combo guns" are mounted with these.(oop chnged the AA to Leupolds just befor the pic. Still playing with getting it set up)
http://www.leapers.com/prod_detail.php?mitem=Mounting%20Systems&itemno=MNT-DT2PW01The Bernedelli has a slot at the very back of the rail for a stop pin. I just drilled and tapped a hole at the rear of the adaptor for a #4 allen screw and dressed the head to fit the slot worked well.