I decided to fit central locking to my Austin A30 because the lock was on the wrong side of the road for our country. First of all, the door of an Austin A30 is very narrow, the only place to put it, whilst retaining the original doorcard is underneath the window. This requires an extra pivot point, I have some pictures and dimensions if you are interested. I puchased a universal central locking set. This set comes with two solenoids that you have to wire (with 4 wires) to a central electronics block.
Here you can see how I had to modify the lock by introducing a sliding bolt made up of some sheet metal and welded to the original lock mechanism. I machined some slots in the slider, these can easily be drilled and filed as well
I have this in the door for almost 10 years now. I did have one motor fail. This was because the wires wore through on the hole in the door (were I have them exiting) be extra carefull here. You want to put extra isolation tape on the wiring and add a well fitting rubber grommet
I have wired an extra hidden switch that opens the doors, just in case the remote dies. Have not used it so far... also, the handle springs are a weakness. In my setup, the handles need to be in a horizontal position to be able to lock. Make sure the mechanism is clean and properly lubricated. It should not be a problem
General tips Use plenty of isolation tape where the wiring goes though the door Use a snug fitting rubber gromit Wire a (hidden) switch to the manual override in case the remote dies.
