[Arran]

You could used the German ones as filter capacitors if you connected them in series, like two 400V 2 uf units in place of a 1 uf unit. Really, paper capacitor values in an old radio are not that critical, especially in a power supply, most others were used for coupling or bypassing, if they are 10% low it won't matter, sometimes 50% low won't matter either. Any place where they needed a precision capacitor they were usually of a small value so the manufacturers typically used mica. Most of the time the micas are still good but do fail on rare occasions, I would leave those alone unless everything else has been ruled out.
Regards
Arran