It is possible that the 3 seats is a mistake. If it has XX7 on the plates it is a Sandman. But if it was not made in Brisbane and therefore does not have the XX7 on the plates then it would be really hard to convince anyone that it was a Sandman as proving it is a mistake would be difficult. Looking for signs of it being originally a 2 seater could be useful but not definitive. Someone with more knowledge than me might be able to tell the difference between factory floor mounted console brackets and ones added later on I guess.

It may be a Sandman with a mistake on the tags and if it was then that would be great for you to know that and appreciate the ute but difficult to convince others of its status.

At the end of the day they are really all just the same and apart from the perceived value and therefore increased prices of a genuine Sandman just as much fun to own , drive and enjoy.