this would be hard, such little combination were build for ligth weight with a small shotgun caliber and similar small rifle caliber. they were taken when being in the hunting ground out of the season to react on smaller pest or when hunting only on small game.
the closed season is the "Schonzeit" so this was called sometimes "Schonzeitgewehr" - closed season gun.

here is a newer typical example, voere combination gun in .410 3" and 22 hornet
https://www.egun.de/market/item.php?id=19017169