I have 2 such combinations:
a Ferlach-made cape gun, 11,2x51R Kropatschek-Heissig (simply a shortened .43 Mauser) and 16 gauge, with extra shotgun barrels, made around 1894
and a Merkel Bockbüchsflinte 7x57R and 12 gauge, with extra shotgun barrels, this one made 1966