Never Seen Before Kaisoku Densha Variant?

Our team did prompt research:


First image shows no chassis clips.


Second image shows chassis clips.

Same Densha Yellow box. Same box art type with Kaisoku Densha in topic. Same generation Densha Yellow. Same generation as the Kaisoku Densha in topic.

First image is from Plarail Museum, Second image is from our teammate's collection.

First image is final production version, Second image is mass production version.

Kaisoku Densha box is safely assumed to be the same. We have found the answer. This is the power of our team. Case closed.