The LL C424 shell fits over the Atlas C420 mechanism very well with just slicing off the 'ledges' on the ends of the frame.
I've seen some of the DVD cuts from the early 70's that shows virtually everything the N&W had running on AJs- including some high-hood GEs. Units with and without DBs, high and low hoods, you name it and the N&W ran it. There were a lot of consists with a single WM unit up front and multiple N&Ws trailing. And a wide variety of N&W cabs in multiple paint schemes. Almost (but not quite) as interesting as the WM itself!
I have to say that I have not seen an ex-Wab F7 in any of the shots, though. If the power originated in Bellevue there would have been a chance they did run there.
Bruce