I have same age Sauer & sohn 16 cal. shotgun. It has greener bolt but despite that I wouldn´t convert mine to double rifle for two main reasons: First, triggers pull is quite insensiteve, even stiff. I have noticed that even some russian cheap s&s has better ones. In my shotgun firing pins are angled so that it would be quite a work to change them and make pin holes smaller. IMO any shotgun action with disk set strikes would be much better alternative.