Yea, original ODO comes with 180km/h speedo. The nismo ones comes with 320 km/h which means they have been changed. They will document it if they have changed it, so try and find those papers, if they don't, then they have probably swapped it for an ODO with lower K's, so check the car for wear and tear and hopefully it matches up to the K's on the dash. My car came with 47,000Kms, original dash, and the carpets and seats are mint!
When something is missing, double check everything! Ooops I can't find it would worry me!
Keep asking questions anyway, we'll try and help you out as much as possible!