Pontiac Streamliner

I'm getting conflicting information.... Maybe you guys can help me out. I thought that the last Streamliner was in 1950. But I see photos of some 51 and 52 streamliners out there.... Did someone just take a 49-50 streamliner and put a 51-52 grill off of a cheiftan on it?? Did Pontiac make a Streamliner past 1950??

Thanks for the help!!!

 

Lets see some of the photos?

 

http://www.pontiacuk.com/id51.html

This link is where I found them.. They are in the UK, so maybe that has something to do with it.. Also, the NADA price guide (not that they are accurate either) has the streamliner all the way out to 1954...