Sorry to add to the confusion! I thought you were after the catalogue
numbers for the 500mA Slow Blow Fuse. I think this is the information
you are after (Taken from the Doepfer FAQ):

If you have a 650mA Power supply:
For 115V mains supply (or thereabouts) you need a 125mA fuse
For 250V mains supply (or thereabouts) you need a 250mA fuse

If you have a 1.2A Power Supply (referred to as PSU II)
For 115V mains supply (or thereabouts) you need a 250mA fuse
For 250V mains supply (or thereabouts) you need a 500mA fuse

It appears, from their online catalogue, that Radio Shack do not sell
Slow-blow (Time Lag) fuses under 500mA.

Cheers,
Adam-V.