Dear Pab567, i'm guessing that you are connected to the MIB_helper channel on YT and the MIb software tools? If so, thanks for making these resources. I tried my unit's serial number at what the MIB site, but it was not recognised - perhaps because it is too old.
I'm going away for a couple of weeks, but I would be interested to research what "modern" nav units can be fitted instead of the Columbus. It's not bad, considering the age, but it's not as well integrated with a modern iPhone as it could be and for sure there could be lots of nice features i don't even think of having now, by installing something new.
many thanks to everyone for comments, very helpful and much appreciated. Nice to be able to keep my car running well!
cheers
Miles