AC/DC radios utilizing a simple half-wave rectifier arrangement were made into the 1960s here, but DC-only is something unusual (not counting battery portables, of course).
Some models made by Bush (and maybe other companies too) sold in both AC/DC and AC-only versions, and in some cases a "field conversion" kit was available. Quite why they produced a transformer-based AC-only model in addition to the AC/DC version is something of a mystery.
