And, as I have been instructed by my tank car tutor (Jerry Stewart) 1917 GATC
tank cars came in several variations, but all of them shared a new mandatory
construction feature - those DOUBLE ROWS of rivets. Prior to that time only a
single row was required.

Tim O'Connor

A lovely shot I thought y'all might enjoy, even though the car's
repaint date is a little too modern.
https://www.ebay.com/itm/362301906033

Yes, and an early one: "Built by GATC 7-17".

David Thompson