[Arran]

 I don't think that it will be too difficult at all to construct a power supply for this radio. For the "A" side a 6.3 volt transformer, with a center tapped secondary should do the job, just wire up the 6.3 volt winding as a full wave rectifier with a grounded center tap, then you will have 3.15 volts to filter and drop down to 2 volt DC at the proper current level, a combination of a silicon diode and a resistor shunted across the output should do, without a voltage regulator you will need a proper filter choke, a resistor won't cut it. For the "B" voltages, a transformer with a 150-200 secondary should do, with a bridge rectifier, then a Pi filter arrangement, either RC or LC, followed by a voltage divider to get the two or more B+ voltages you need. Probably the easiest way to construct a power supply for battery radios is to use a power transformer from a scrapped AC tube radio, preferably from a small set like a five tuber, the only drawback is that the high voltage winding is often a little too high, like 180 volts on up, which you will have to reduce.
Regards
Arran