There has been no re-occurrence of the issue!
Done quite a few day trips and 5 days touring Pembrokeshire, I recorded all the trips with Torque Pro and the logs show no drops that we may have missed visually, so as confident as I can be that it's resolved
I'm confident that the issue was a CAN-BUS problem within the Chassis Harness but as per my previous post the cause is either
1. a dodgy connection within the Chassis/Engine Harness connector OR
2. an issue with the CAN-BUS wiring Splices which sit just in front of the same connector.
I'll tidy the wiring back up at some point and report back here if the issue returns (or not).
Thanks again for all the help chaps.
Regards