All Z-1 bodies are the same. There is a Z-1, Z-1S, Z-1E, Z-1EB, Z-4 which is also a Z-1 and a few others.
This is a wrong information: all the cartridges Z1 are different. I have Z1, Freq. Response 10Hz - 50kHz (close to X1); Z1 EB (Elliptical Beryllium), 10Hz - 35kHz; and Z1 S (with S) was the cheapest option even with spherical stylus.
You can find recordings of the Z1 sound (with Jico SAS) and X1 IIE in Ytube (Porco Stereo channel), just like an idea.