Hornby from England quit making 0 gauge trains around 1960. Some smaller manufacturers still make Hornby replica trains; I show some freight cars. Ridg(e)ley makes in his Directory Series painted and decalled freight cars; Middleton from Australia makes lithographed tinplate versions. The cars pictured all have Märklin couplers which I assume were added by the previous (German?) owner.
Regards
FRed