Hmm... this discussion got me to wondering if Archer Surface Details would help me scratch build a roof on a DT&I rebuild from 1936.  I don't think that the half-round styrene shapes are available small enough to replicate the riblets on the Cambre radial roof shown here:

http://dti.railfan.net/Equipment_Database/DTI11000sUSRA40%27dsBox/ArtDTI11500s.html

I don't have any Archer sheets to look at, can you give me an idea if they would work?  I bet there aren't too many Cambre roofs out there!  But, I don't think you can build a convincing version of this car without that roof, and I have a soft spot for the oddball rebuilds done during the 30's.  Plus, Detroit is the northern terminus of my road.

Dean Payne