Wow, it's funny how a dead topic can get revived over one question. So I ended up getting the (6-18099) Conventional Lionel SP 2282 Camelback (Picture). Right around the time I purchased the camelback, wouldn't you know it, Lionel came out with the Legacy version of the Camelback. I have been looking at the way gunrunnerjohn suggested and have been sitting on it for some time, distracted with other projects.
I got to wondering, would it now be possible to convert this conventional Camelback to Legacy? Or would it would be a better option to purchase a legacy Camelback and transfer the shells to the newer engine? I know that this is crazy but what isn't in this hobby. Other than the hole in the chassis for the whistle, the casting for the engine and the shell for the tender should still be the same, yes?
Why do I care about all this? I like oddball motive power, the Southern Pacific was good for that. They would acquire smaller railroads, along with their equipment and end up with one off's. Like the only Camelback in their roster, when they merged with the Sonora Railroad out of Mexico.
Real life SP camelback