Sounds like the internal bar between the key slot and ignition switch it's about 6 inches long with bumps and lumps and disengages the steering column lock you can strip all the plastics off and have a look at the lock it is possible to release the steering lock and do a screwdriver start if you are confident in you work or ex joyrider as for some spare parts you can try Gary @ 80s breaker he has hundreds in Chapelgate got a hundred ad floating about or Karl Webster he might have hundred spares and that's me brain drained for the rest of the day