Vintage truck body: Welly to K-Line to Lionel?

I do not know the answer to your question. I do have many of this model truck from K-line, some with the Coca Cola markings, for the price they are nice trucks. I am not a fan of the chrome wheels and have started to paint the wheels with black paint and I do like them much better.

Yes, with a little detailing these trucks look very nice.  I also paint most of the wheels, and on the ones without window glass (I have one with) install that, other tiny details, etc., and often add a full box truck body, made a firetruck, etc., too.    They really make nice vehciles when fitted out a bit, as long as you don't have too many on the layout all in one place. 

Molds for 'toys' and models in Hong Kong float around a LOT.  Many times owners close shop stateside and the molds then end up with whoever had them last. They are also leased and 'borrowed'  between the small group of manufactures in the region. It happens often in the plastic model field that I work in. So no hard info here....but SOP in China.

Lee those trucks have been around for a long time...longer then super streets. I don't know about Lionel but K-Line did re-package them besides other brand name vehicles.

As you can see in the DD ad they are cheap.

Bob