Everts no longer flying theirs?
Yes, they are, and so is Northern Air Cargo.
However, technically, these are DC-6A's or DC-6A/B varients.
Size, systems, engines, weights etc, just about the same.
Note:
The DC-6B was, and still is, the most economical and reliable 4-engine piston transport...ever.
It's revenue/seat mile cost simply could not be beat by any other 4-engine type.
My dad was engineering project manager on this type (DC-7 as well) at Douglas, and the company was very pleased with the -6B, and so were a lot of airlines that ordered it.