[Test-Equipment] SPM-19 <=> PS-19 cable

[Gollum]

I have a W&G SPM-19 Selective Voltmeter and its companion, the Level Generator PS-19.
The two are meant to work together in tracking mode, being connected via a special cable.
I don't have that cable. The connectors on the back panels are mechanically compatible with the GPIB connectors.
Can please somebody in the know tell me if I am safe using just a GPIB cable, or do I risk to fry both instruments ?
Alternatively, can somebody point me to a source for that cable ?

Many thanks

73  Alberto  I2PHD