@Don McErlean I seem to have the same version I picked up on Ebay last year for $29. But I am not sure if it has the thick or thin axles. I assumed it was from 1939-41, because that is how I interpret the text in the TCA book:
"DUMP, 4-Wh. 1931-34.
orange-RS
medium green-RS (uncat.-circa 1939-41) "
I read that as the green are all from the later period, but that is not correct? Like @Rich Wiemann, I'm surprised the book doesn't go into more detail and differentiate the 4 and 5 line stamp.
Anyway, a charming little car and it carries and dumps candy on my Christmas layout.