I think you refer to the 'Range Rover on Board Diagnostic Display' part PRC17EM. There are a couple on ebay, but located in USA. I do have one but problem is that the ECU harness needs to be fitted with a socket to plug the display into. A guy called Steve Heath made a similar device that plugs into the diagnostic port, but Steve probably found other things to do and stopped making them. Steve also made a diagnostic reader called ECU Mate, which is very good as stand alone reader, only available pre-owned and none on ebay at the moment. In any event, the Rovergauge is a much more complete diagnostic tool and at £35 for the cable and a CD it is good value
Couple of points. Assuming it is the same as my 95 Plus 8, there is no MIL light, so you may have error codes logged, but won't know until you connect a reader. What may look like a MIL light illuminates when the inertia switch fires and isolates the fuel pump. A second issue can be that using the battery isolator (the red key) will cause the ECU to reset and lose any stored codes. So when you get the fault, read the codes, don't turn the red key before you read them.
