Bill, I am wondering about another approach to the 10' IDE end.  I did this same DL&W car kitbash this summer using a similar approach (Southwest doors, diag. panel roof) except I used an Intermountain 10' IDE end with in conjunction with the pre-war 1937 body.  I may have missed something in the accuracy of the end, but it looks pretty close.  Not sure how easy it is to obtain a pair of those 10' IDE ends.  I happened to have a set.  I used the DL&W decal set (formerly Jerry Glow) now available from Tichy.