Take another look at that Red Caboose Barber S2 truck. As I recall, the truck bolsters are lacking the two wedge shapes visible at the ends. Inside these shapes, the real trucks had the spring loaded wedges that pressed against the columns. Without those, the truck cannot be an S2.
And Atlas's attempt had wedge shapes so lightly engraved they can hardly be seen.
Exactrail and Branchline S2 trucks were both done by the same mold maker. The journal boxes on both are WAY too small.
When I tooled the Tahoe Barber S2 truck, I worked with the real trucks under a Milwaukee Road box car at the railroad museum in Portola, CA, and got to touch and measure the real thing. Like the prototypes there, the Tahoe truck replicates S2 trucks with spring planks.
Tahoe Model Works
Carson City, NV