What do I have here???

I recently purchased a Lionel Flying Yankee at an estate sale.This particular one is completely smooth with no ribs and no chrome.It is painted Silver,and has a Black Top on the engine.What year were these produced?,and are they rare as I thought they were when I purchased it?Also,would you restore it,or leave it just like it is???I cleaned and lubricated the motor,and it runs like new!!!I have a video of it posted on You a Tube,my username is: streettrain77.I will attempt to post it on here,and a few photos.I am a truck driver and I am out on the road in NYC right now.Please help me to better identify this train and it's rarity and estimated value.Thanks!!!