Early Mk2 Granada C/L door locks fit straight in as do Mk3 escorts door locks with C/L but they're not multi-point (they only lock/unlock from the drivers door), which means you'll need to fit a servo to the drivers door to open the rest up. This type are a bolt in fitment (except on the rear doors you need to bend the inner door skin a bit)

You can fit a complete C/L system from a Sierra or Mk4 Escort, these are multi-point (lock/unlock from both front doors) and will unlock from an alarm just by wiring it in correctly.
The Sierra/Escort Mk4 system uses servos with relays built in and are easier to wire in but need adapting to connect the servo's to the lock mechanism already in the doors.

With both systems you'll need to drill holes in the door pillars and doors for the wires to pass through.
 

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