Mustang alarm advice

[38HAULR]

Hi Guys, I am calling from OZ,I have purchased a 66 Mustang,this vehicle is fitted with a "Python 650" immobiliser,which appeared to be inactive.There was a red led  on the dash constantly on. I have just completed  fitting a pwr assisted ,dual cct disc brake system,and had disconnected the battery whilst working under the dash.When I reconnected the battery the immobiliser has come to life,there is a siren in the engine bay that is not connected,the remote with the keyring ,now with a good battery works ,and I can immobilise/de immobilise the vehicle.My question is is there any one who can assist with the correct operation of this unit.I am after the wiring if poss,and also if this item can be clicked into "valet" mode, ie bypassed....Thanks   .Frank.