Shurlok alarm immobiliser instructions

[Sportsman]

My 1994 NA Clubman is fitted with a Shurlok alarm immobiliser system for which I have no handbook. I’m concerned that if I remove the car battery it will activate the alarm/immobiliser and I have no key or code to disable it. I have searched for a Shurlok agent locally without success. Can anyone suggest where I might get a Shurlok handbook please? Many Thanks Sportsman