Mr prototype is correct. From what I have read soldering doubles is tricky. Not that you couldnt do it, it just takes some practice. I used to visit an old school gunshop that did this kind of work. a guy brought in a double he had tried to solder and had the upper and lower ribs come lose for his troubles. The smith told me you have too clamp everything in place before applying heat. I would think that some heat stop paste would work in this case. Anyway, be sure to show us the finished gun.
"NA BEAN DON CHAT GUN LAMHAINN"