In my humble opinion it's the Lionel JLC Norfolk & Western Y6b 2-8-8-2 #2200. TMCC and late RS4, it is a magnificent model with a piercing, unforgettable hooter whistle that's never been replicated. The Y6b pictured here parked at Roanoke and awaiting its crew call recently ran on Eliot Scher's railroad. There are two more just like it in the DUTRY roundhouse on Duck Island.
The last photo is a rare K-Line car that George Lasley and I are "improving" (and it was pretty good to begin with). The heavy well flat with four trucks carries a ship's propeller (properly called a wheel) en route to Norfolk for installation on a Duckunder Marine coastal coal vessel. The model is diecast and very heavy. So far we've added a wood deck and painted the fixture holding the wheel blue to distinguish it from the car. More changes coming.
Happy holidays to all!