Gearbox number confusion

[OzDave]

Hi everyone, I’ve applied to get a heritage certificate for my recently purchased series 3 roadster. They have come back questioning my gearbox number stating that it may have been misread. It looked pretty clear to me but the last digit may not be fully stamped. I’ve attached a picture of the plate. Does anyone have any ideas about the gearbox number being something different than KL6690?

[bitsobrits]

I read it as a "5".