My New (to me) P38 with electrical challenges

Ok all I am looking for some help bought the P38 and drove it from Birmingham to Livingston then Livingston to Aberdeen and back the car runs well, however there are a few electrical gremlins that i am looking for advice on which are listed below

Central locking doesn't work, at all, it doesn't work off the remote, doesn't work off the key and doesn't work internally (by lifting the driver/passenger door catch)? I was told that the problem arose after the gas was fitted but suspect that is not true

Boot has a security feature, you can only open it using the button if you put it in reverse and turn on the ignition, most of you will have quickly worked out that it is being powered by the reverse light, I was half way up the M6 before the eureka moment hit, but how should it normally be powered up?

SRS airbag light is on it starts off flashing then goes to steady red?

Crusie control is not working the light desn't come on at switch, is there a fuse I can check I also need to know if it should work while on Gas? (last gas powered vehicle I had was a Disco but didn't have Cruise)

Also looking for a door latch (the wee grey bit you lift to unlock the door in grey) if anyone has one available? I have found the surround but not the latch, and local scrappies don't have RR's only a disco, not in a hurry as I need to wait for the front window regulator and hope to change it all then.

Thanks for any help

Oh! forgot to add it keeps telling me that the front Offside/main beam bulb has failed when it is clear that it isn't, driving up to and back from Aberdeen on Sunday night.