Does the original cartridge have two mounting screws, that are spaced approx. 1/2" apart and does this record player have a preamp stage ahead of the final output tube? If so, I'd use a modern cartridge like a Pfanstiehl P228, available from
www.thevoiceofmusic.com. This is a stereo cartridge and the two channels will need to be wired in parallel for mono. The VM site also sells a P228 based cartridge kit that will allow mounting in tonearms that don't have the standard 1/2" mounts.