Point 63a of Maltby's report places it at Tai Tam Gap (alternate spellings: Ty Tam, Tytam), but I'm not sure of closer directions than that:
(a) At 1900 hours 18th December three armoured cars of the HKVDC were sent to Tytam Gap to be a mobile reserve in the hands of the Commander East Infantry Brigade at his HQ there, and two other cars remained in hand at Leighton Hill close to i Middlesex HQ.
East Brigade HQ
Point 63a of Maltby's report places it at Tai Tam Gap (alternate spellings: Ty Tam, Tytam), but I'm not sure of closer directions than that:
MrB