No DCC here, so if the shell physically can fit on the frame except for a minor notch that can be removed, this sounds like
it will work. A BIG key is whether the wheelbases are identical so the trucks will sit in the shell cut-outs correctly.
As for the crazy wiper system in the LL, most likely, I would get rid of that and mount some new wipers that
are permanently attached to the frame, leaving the shell out of it altogether.
Thanks for the info.