Wanted: Cable for Protovale Covermaster

Greetings everyone,

Our lab master has recently obtained a used rebar locater and cannot find the cable that connects the sending unit to the receiver/display. He has called the new distributor and original manufacturer neither of whom would give him any help. They wish to sell him an entire new unit. It appears to need a polarized cable that is coaxial on one end with a four pin connector that appears to use only two pins on the other. Inside investigation revealed #s filed off chips etc that gives almost no indication of how one would correctly rewire the plug. He does not wish to make grave mistake in rigging up a substitute. The unit in question is a Protovale Covermaster, CM4 serial # 59433 that was originally distributed by the Gilson Company. If any knows where to source a cable or knows exactly what we need to fabricate, or even better, has a schematic it would be deeply appreciated. We would even take you fishing if you ever come to Juneau Alaska