This vehicle is probably SXF 106 or 108, but there is no way of knowing. The chassis number puts it between 105 and 109 (with 107 in between), but with a 28-number gap and only 2 registrations to go at, there's no way of knowing for sure. There is strong evidence to suggest that it was a Reconnaissance vehicle.
The present owner is trying to trace the original registration in the hope of getting it reunited with the vehicle, which is being restored.