Private Reg

Okay so i bought my first ever car 2 weeks ago from a car auction. There is a private reg attached and the auctioneer said if the winner gets to keep it then its a bonus. So anyways i won and asked the guy at the desk when i was paying for it, if the reg came attached. he said "all i can say is to hurry up and pay the balance so we can send the logbook off" so yeah basically that arrived this morning. in big red letters on the front it says "the document is not proof of ownership". So my question is? how do i know if i get to keep the private reg? and how do i show i own the car? thanks!

I been in this game a long time and a little lost with your Q,,, would you mind provide the name of the auction - location - date - and how the draw was done - vehicle you got - how much ? send the log book off ? what is :banghead: this ?