I have a cheap Stoeger Uplander with screw in chokes that I am going to use rifled tubes with. I have come up with an idea (unproven of course) to use a single rear sight and a wedge shaped front sight. The point of the front sight would face towards your eye. In either side of the wedge would be a brass insert to sight off of. If the gun crosses, you would aim the opposite side (barrel to wedge) If it shoots apart, you would use the same side. Once you get the correct alignment, it should just be getting used to which side to aim. My other thought was a t-shaped sight with one of the bright fiber optic sights mounted on each side of the T. Maybe red and green....just like boat lights...port and starboard! These sights will be mounted to machined extension that slides on to the extension of the choke. Should take some of the stress off the double's barrels and also be removeable.
I will let you guys know how tis works out.