If a 10 plate Scudo was left with a dead battery for weeks (months?) Would the odometer default to km's when a new battery was installed? The odo shows 39000 miles but the new mot shows 62000 and that's the explanation I was given (both mechanic and tester missed it). Is there any way of verifying the mileage via the ecu as it obviously will be an issue next time it's tested even though I'm confident that the mileage is correct at 39000? TIA.

Would checking back the old MT's help?

https://www.check-mot.service.gov.uk/