Nicely done! Now I'll let you guys in on a little secret we S gauge guys have been doing for years, especially in the Dark Days of S when Lionel and American Models weren't doing any S. You can buy a Scout shell for a few bucks at a local train show and put S trucks under it and it makes a very credible car for very little money. Its dimensions are almost spot on for 1:64 scale. Some guys grind off the molded in details and add separate ones. It all depends on how far you are willing to go. Personally, I feel that from 3 feet away, the molded in details aren't all that noticeable. The only thing I did was to add a bit of plastic strip to finish off the outside bracing, then paint and decal the car. Here's what I mean:
First, strip the lettering and add the plastic strips:
Then paint, decal and add the underframe and/or trucks:
I've run the car at train shows and 99% of those in attendance cannot tell the car's origin unless the train is stopped and you look closer.
Hey, it's called "having fun with trains" in my book!