Ingnition barrel repair

Just wondered is it possible to refurbish/repair the ignition barrel/steering lock.

The starter motor solenoid feed was showing no power on the switch terminal when I first came to try it, but after a lot of messing it sudeny started working.

Worried it might fail again, so would like to strip and refurbish if that is possible.

It has the diesel stop pull, so I don't think I can just swap it for a defender type or similar.

Short answer is yes, take the cover off to see if the shear bolts holding the lock on have been sheared or not. If so order new ones or plain bolts, I can not remember the size but think 5/16" UNF depending on the model year. With the lock assembly off (I drilled and used easy out stud extractor) the switch part with the electrical terminals is held on the back with two small screws. You may get away with a contact spray cleaner. I did see reference on the board or another forum recently to new switches being available.