My two favorite resin casters are Rep.&Min. Co of Md., and Modelhaus Resin. That wagon body (and interior) had absolutely NO pinholes in it! Also, the prep for paint was simply washing it with dish soap. I did another company's resin body a while ago that had pinholes all over it. I got this kit at last year's NNL East, where they were a vendor, at a good price, saving shipping, also.
Dale and Mike, I think you're right, I'm going with the 409!