As the entire railroad was being dismantled at the time I would say that the frame was scrapped and the running gear was sold or scrapped.
The frame for the car body was mostly wood. Only the car end frames and the bows for the arched roof were of steel. The plan is to get one or more of the coaches/combines back from Alaska and see how the under frame etc. was built so we can replicate it. As previously mentioned, the return of one of the cars is just waiting for the White Pass to release it. The restoration of No. 4 is not even on the back burner, more like the warming oven.