My guess is that it is the Blue Comet 400e 1931 to 37. Lionel or MTH made a repro in the last ten years or so. Doyle list it as 3000 mint in blue, black crackled is 6000. Three blue pasenger cars of the 400 series not the small ones shown ( 150 each)are 1000 each in mint condition.
I doubt if it is original.
I doubt if it is original.