Update my nexus one to Gingerbread ?

[samw1038]

Hi, I recently bought a Brand new Nexus one of eBay as i have always loved them and decided to buy my self one. Im not anything new to Android ( i already have a Galaxy Note 3 and a 2013 Nexus 7 ) but my N1 has come with 2.2.1 Froyo and i know these can be updated to Gingerbread but ive had no Notification to update and ive been using it for 3 days now. Even if i go to settings and system update and tap on that it goes straight to a screen that says " you already have the latest updates" or something along the lines of that but it doesn't even appear to check when i tap on it ? So i was wondering if any of you guys have a solution or know if the update is still available ?
Thanks Sam