Two good choices for a DG safari ... if one has a good gunbearer.

The .375 Flanged for plains game especially larger plains game. Cats. And fine shooting on buffalo and elephant.

The .577 for thick stuff, follow up, stopping rifle or maybe preferred for buffalo and especially elephant or in the old days black rhino.

Add a 7x57R as a third scoped double and other than small game rifles and shotguns one needs little else. I'd want the .375 scoped as well. Maybe it might perform adequately without a scope at closer ranges if regulated for a scope. Maybe a heavier dot point would work if the scope was removed?

I wonder why they put the ugly chunky beavertail forend on the .577? Hardly needed for a hot barrel if firing too many shots with a .577! Perhaps for additional weight? Beavertail forends are grossly ugly.

I'd put an bull elephant engraving on the .577 if it was mine. Whens that lotto win coming?!