The 2009 song Roll Along which originally ran for over 1 minute and a half aired in one of the 30 minute shows recently, but in it's supposed full 2 minute and 10 second form.
YouTube. The music video features more clips from the series and lyrics never before heard in the UK.
US fans who watched the Thomas and the Runaway Kite theatre screenings might have seen the full version at the start of the performances.
You can watch Thomas & Friends - Season Thirteen for half an hour at 12pm on Nick. Jr in the UK.