It is extremely important that you are a Scottish resident. However, when you say you appealed (futilely) to TRACR, did you reveal the drivers identity, inadvertently or otherwise? Unless the Keeper plans it, they have no idea who the driver is. In Scotland, there is no Keeper liability.
You should never, ever, EVER communicate with useless debt collector. Debt collectors such as TRACE are powerless to do anything except to try and intimidate the low-hanging fruit on the gullible tree into paying out of ignorance and fear.
Regarding your address at the time... your drivers licence and insurance are totally irrelevant. The ONLY document that is used to get the Keepers details is the V5C. If you failed to update that after a move, then you could also be in trouble with the DVLA.
So, have you blabbed the drivers identity in your communication with TRACE by saying things like "I did this or that", instead of only referring to the driver in the third party with "the driver did this or that"?