You've got yourself a pretty nice set there! congratulations!

aKmike: To make it functional with both barrelsets you need to substitute the left shotgunbarrel for a riflebarrel on the doublerifle set: This because the front trigger works on the right barrel, and the lower barrel when the selector is set on "Kugel"="rifle". That way you get both triggers to work on the shotgunbarrels for instinctive shooting, and the riflebarrel ready as you slide on the selector. When you put on the doublerifle set you've got a functional doublerifle, and the choice of the shotgun if you'd like when you slide the selector backwards.

It's more common with the riflebarrels on top, but that put a lot more stress on the action, and the setup isn't very functional with BOTH barrelsets..

I've got a Sauer und Sohn drilling in 16/16/7x57R and enjoy it a lot! It takes some shooting to get used to, but when you do, it is a wonderful gun! I whish I had a double riifle set like yours to go with it.
A cheap option is to get an insert barrel, that's what I have in mind, and I'll put it in the left barrel..

All the best with Your new Drilling! I bet you'll never part with it as you get to know it!