Hey mate,
i think you'll find its "etched" not "engraved".
As far as i know, its just the tool that was used on the 34's build plate as mine is also like that and im quite sure that the 33's had printed with a different tool.
incase your wondering, the best way i can describe etched in this situation is the feeling that there is some roughness on the plate, but no actual depth to it, which would indicate that it is normal, if you can feel depth to it, that may indicate it is engraved and possibly a stolen car.
Hope i made some sense