That is a very old 2 Group ECU. DOcumentation is very limited but I have attached a scan of the hand controller manual. THe wiring drwing can be downloaded from the MoTeC web site http://www.motec.com.au/downloads/downloaddatasheets/.
WOW, I would like to have a look inside the circuit in the transmit modem. Are you able to post a photo of the circuit? I need to make on of these that works.