Faulty scorpion alarm

[grommett]

My car has a scorpion alarm which looks like it was probably fitted when the car was new in 1987. It was disconnected when I bought the car - the multi-pin connector was pulled out of the black box under the dashboard. When I plugged it back in it started making a clicking noise so I left it disconnected. I would like to get it working as apart from anything else I imagine it would give me remote central locking (I had a similar system on an XR3i in the 80's!). I can live without it but it would be nice to get it working. Can anyone tell me where I can get a replacement unit or get it repaired? I have tried searching eBay and have only been able to find very similar units which have come out of mercedes etc. but not porsche and I am not sure if they would be suitable. Any advice would be appreciated.